Prior to World War II, control activity in the United States was mostly in the design of electronic feedback amplifiers and in chemical process control where the PID controller was king. During the war, these technologies were merged and vastly expanded to meet the needs of military systems of all types. These included control of aircraft, bombsights, radar, artillery pieces on land, long range guns on ships, and torpedoes. This set the groundwork for a comprehensive theory of servomechanisms based on sophisticated mathematics and implementation using vacuum tube-based electronics. A major center of this early work was at MIT in the Radiation Laboratory. After the war, the results were reported in the 27 volume Radiation Laboratory Series published by McGraw Hill. Volume 25 of that series, published in 1947, is entitled Theory of Servomechanisms by H M James, a Purdue physicist, N B Nichols, a process control engineer from the Taylor Instruments Company, and R S Phillips, a University of Southern California mathematician.

Very few engineers had PhDs in what we would now think of as control science. Much engineering work was done by classically trained physicists and a small fraction of the work was devoted to atomic weapon development. In the United States, much of the control engineering work took place at a few institutions including General Electric, Hughes Aircraft, Bell Labs, Minneapolis Honeywell, MIT, Los Alamos, UCLA, Columbia, Westinghouse, and Leeds and Northrup. The war effort had prevented wide spread communication of technical advances although there were a few examples of small groups of contributors, particularly in the US and England who were in close touch about military technologies based on control ideas. There was almost no public communication of advances in control in academic institutions, few journals and conferences, and very little international sharing of scientific ideas. Little of the foreign literature was translated into English, which also contributed to the isolation of ideas in the world.

Harold Chestnut imageA few textbooks that contained basic control science concepts appeared prior to 1950 and it was in part through these few books in English, or translated into English, that an international community began to understand the potential for control to emerge as a separate field of scientific coherent scientific study. These included the English language books by MacColl, Eckman, Lauer et al, James, Nichols & Phillips mentioned above, and Brown & Campbell. In early 1951 what became the most influential of the early works was the textbook authored by General Electric Company engineers Harold Chestnut and Robert Mayer, Servomechanisms and Regulating System Design. By 1957 it had appeared in seven printings and had become a standard for engineering academic programs and was in wide use in the burgeoning control field in industry in the English speaking world. This book was in what became the traditional style of the academic textbook in control with a strong pedantic approach including numerous homework problems in each chapter. Many of the other existing books were either summaries of war-time developments, or focused on specific applications areas in engineering.

Largely due to the popularity of his book outside the US, Harold Chestnut was one of the best known American control engineers during the 1950s. Rufus Oldenburger of Purdue University was also a well known US control figure at that time and in fact had the initial germ of an idea about what later became the International Federation of Automatic Control (IFAC). His role in the initial Heidelberg meeting in 1956 was instrumental in the founding of IFAC. However, his other obligations did not permit him to take on a leadership role in the new IFAC and he suggested to his international colleagues that Chestnut would be a good candidate. The Chestnut book had made him a well known name among this organizing group. When the time came for IFAC to be created, Chestnut was therefore selected be the first President of IFAC. In order to accommodate an international balance across the Iron Curtain, the Russian Alexander Letov was selected as the Second IFAC President and he would preside over the first IFAC World Congress to be held in Moscow in 1960. IFAC presidencies change only at IFAC General Assembly meetings. The first of these was held in Paris in 1957 where Chestnut was elected. The second IFAC General Assembly was held in Chicago in 1959 when Chestnut's term ended and Alexander Letov was elected President and went on to host the first IFAC Congress in 1960 in Moscow. Although many of them were unknown in the West at that time, the Russians had been making important mathematical contributions to control theory for decades particularly from the 1930s at the Steklov Mathematical Institute led by Pontryagin and the USSR Academy of Sciences Institute for Control Problems in Moscow. IFAC would eventually be the vehicle for communicating many of these world-wide.

Founding AACC

One of the founding principles of IFAC was that there would be a single National Member Organization (NMO) from each member country who would be the formal member of IFAC. These NMOs had to reflect the interests of control engineers across all disciplines in that country. Although several professional societies were involved in control activities, there was no single organization in the US devoted to control across all engineering disciplines. As a result, during these earliest days such a US NMO was created and called the American Automatic Control Council (AACC), with Rufus Oldenburger as its first President. The initial AACC consisted of Officers and Directors with each Director representing one of the founding engineering professional societies in the US: American Society of Mechanical Engineers (ASME), American Institute of Electrical Engineers (AIEE), Institute of Radio Engineers (IRE), Instrument Society of America (ISA), and American Institute of Chemical Engineers (AIChE). There was some discussion of including a Canadian engineering society (and using the name North American Control Council) but that did not materialize. The first organizational meeting occurred on March 16, 1957 in Chicago. This was about one month before the critical Provisional Committee meeting for the formation of IFAC so when Oldenburger attended that meeting he was representing the putative NMO from the United States. Thus the formation of IFAC hastened the formation of the American Automatic Control Council. Several other countries who were also likely founding members of IFAC had no such national control organization and set about creating them. By the end of 1957 the only members of IFAC were Austria, Czechoslovakia, Denmark, Hungary, Italy, Poland, the USSR, and the United States of America. Eleven additional members joined in 1958 and by the time of the Moscow Congress there were 25 NMOs in IFAC. Today there are 50.

Early AACC Leadership and Activities

To start the AACC it was necessary to create a leadership cadre, draft governance documents, initiate activities consistent with the purpose of the organization, create a secretariat, and facilitate interactions with IFAC. The first major decision was that members would be American professional societies in the control field. There was concern that if individuals were to be AACC members, that would compete with existing professional societies for membership. It was quickly decided to create an annual technical conference, establish the working relationship with the American engineering societies that constituted the AACC, develop a financial model for operation, and determine how to bring in major contributors to the control profession in the US to play leading roles in AACC activities. It was also determined that two levels of membership would be authorized. Sponsor Members were entitled to have representation on the AACC itself and to be the sponsor of technical meetings taking financial responsibility and managing all aspects of the meeting. There was also defined a Participating Member which was entitled to attend and participate in Council discussions, but had no vote and was not entitled to be the host of AACC technical meetings.

AACC would be financially supported by annual dues from all member societies. All expenditures exceeding $25 required written authorization by the President. Still one other feature of the first constitution of AACC was the need to create a program committee to mimic an IFAC equivalent. In these early days, submission of papers to the first IFAC Congress, needed to be formally certified by AACC and become a "US submission" to fit within a "US quota" of papers for the Moscow Congress. This was a short lived feature of IFAC, which today seems very strange indeed. It was one of several accommodations needed to create an INTERNATIONAL Federation of Automatic Control acceptable to countries on both sides of the Iron Curtain. At least, the official IFAC language was English, which made interaction easier for the Americans than some of our foreign colleagues. The fact that so many of our foreign friends were at least somewhat fluent in English emphasized the importance of multi-lingual dictionaries and glossaries. There was emphasis on terminology and standards in the early days of AACC and IFAC. Even as late as 1975, when the IFAC Congress was held in Cambridge there was a discussion about simultaneous translation, and a decision to finally stop that practice which had persisted in one form or another up to that time.

The early model for an annual national control conference under the auspices of the AACC was that the sponsoring member societies would take turns as the meeting host and take full financial responsibility for the event. AACC was to coordinate the dates and locations of the meetings. The first of these technical meetings, which were called Joint Automatic Control Conferences , was held in 1959 in Dallas. Prior to this first "formal" conference (JACC) the technical activities of AACC were devoted to preparing for and participating in the first IFAC Congress in Moscow in 1960. In those days there were major Congress paper reviewing responsibilities in each NMO. This required extensive effort for the fledgling IFAC and its NMOs. In the middle of the Cold War, there were national quotas to be negotiated. Complex communication and travel plans had to be adhered to just to be involved with Soviet Congress organizers. In those days all Russian control engineers involved with IFAC had a single mailing address in Moscow; personal exchanges were prohibited and all contacts were tightly monitored. There are interesting accounts of the successes of the 1960 IFAC World Congress in Moscow and local efforts in the US to ensure that American papers were reviewed and presented there. The key Americans involved with putting all this together were Rufus Oldenburger (then AACC President), Hal Chestnut (initial IFAC President until 1958), and Jack Lozier (second AACC President and an IFAC President from 1972 to 1975). The Russians determined that the only American citizens who would be allowed to come to Moscow were those whose papers were accepted for the Congress. Thus the paper review process had this added constraint as well – an American not welcome in the Soviet Union at that time would not have a paper accepted! This is a partial list of people in the American delegation to Moscow in 1960: Bellman, Kalaba, Kalman, Jury, Merriam, Aseltine, Tou, Gibson, Bass, Reswick, Axelby, Higgins, Kranc, Van Valkenberger, Bertram, Sarachik, Kirchmayer, Mesarovic, Cohn, Stout, Friedland, Kochenberger, Nichols, Zeigler, Widrow, and Draper. It is hard to imagine the effort that was expended by the AACC team to organize the American contribution to the IFAC Congress in Moscow.

The First Decades

During the first decade of its existence, there were two major challenges for the new AACC. One was support of and participation in activities of IFAC. The other was nurturing the JACC series. As noted earlier, the JACCs were being organized one member society at a time, with the current host being responsible for all aspects of its JACC. Since there was no track record for these meetings, each organizing committee had to start from the beginning. There was no history, no good record of how previous JACCs were operated, no common volunteer staff continuing beyond their own JACC, little experience with conference accounting, dealing with various university administrations for facility use, etc. An early decision of the AACC was to encourage the organizers of the JACCs to host the conference in a university setting in order to keep conference expenses low for the "poorly paid faculty and student" attendees. This, in retrospect, was remarkable since the AACC presidency, with the sole exception of its first President was occupied by one industry leader after another. In fact, in its first two decades, all AACC presidents were from non-academic organizations including Bell Labs, General Electric, Lincoln Labs, Monsanto, Minneapolis-Honeywell, IBM, Aerospace Corporation, Leeds & Northrup and the United States Air Force. After 1980 there was a 3:1 ratio between academia and industry among the Presidents, each serving a two year term. The JACCs occurred prior to 1980 and all but one of the Presidents in that period were industry leaders (one switched from industry to academia during this period) and all the conferences occurred on college campuses. After 1980 all but four of the AACC Presidents were academic leaders and almost all the conferences (now called ACCs) took place in conference hotels around the country.

At the same time the US continued to play a leading role in IFAC. In 1962, a few years after Chestnut's term as the first IFAC President, the US and IFAC suffered a tragic loss when Donald Eckman, a leading systems engineering professor at Case Institute of Technology, was killed in an automobile accident in Europe while travelling to an IFAC Council meeting in Cambridge, UK. At that time Eckman was chairman of what we now know as the Technical Board (then Advisory Committee) of IFAC. John Lozier, an engineering manager at Bell Labs, was Past President of the AACC, an IFAC Executive Council member and would continue on to be the key US participant in the senior leadership of IFAC from the US until his term as IFAC President from 1972 to 1975 when the IFAC held its 6th Congress, this time at MIT. The tradition of holding the IFAC Congress in the home country of its President has remained a consistent practice from the founding of IFAC until the present time. Since the IFAC constitution calls for only one member of the Council for any given country, there have been relatively few Americans who have served on the IFAC Council. In particular these have been Chestnut, Lozier, Miller, Kahne, Masten, and Haddad. More about these gentlemen as the story unfolds.

In the early 1960s Harold Chestnut made a proposal to change the name of AACC to AFACS, the American Federation of Automatic Control Societies. His reasoning included that: a) the emerging organization was really more of a "federation" than a "council," b) the word "federation" was by then well established in IFAC and might more readily convey the idea that the AACC was a member of IFAC, and c) the IFIP (International Federation of Information Processing) and AFIPS (American Federation of Information Processing Societies) pairing already existed and the AACC/IFAC was similar organizationally. In any event, this proposal was not adopted and the name AACC has persisted up to this day.

AACC's Technical Meetings

The JACCs experienced some difficulties as their sponsorship rotated among the AACC members. Not all member societies chose to serve as hosts and it was always a topic of discussion about who was next up as hosts. The meeting had to be planned several years in advance so these discussions pertained to meetings several years out. There was no AACC Newsletter in the early decades so occasional notes in the various society journals were the only early warnings of JACC dates. Since Chestnut's IFAC Presidency did not include an IFAC Congress, very early in AACC's history there was discussion of when, if, and how an IFAC Congress would be held in the US. As is usual with Congress planning in IFAC there are informal discussions among national leaders in the control field from IFAC members (countries) who have an interest in possibly hosting the Congress. These discussions started about one decade before the proposed Congress because the IFAC leadership hierarchy is a fundamental part of any Congress proposal. It is interesting to note that the selection of the site for holding an IFAC Congress has always been a competitive process among several IFAC member countries. The more IFAC matured the more competitive it has gotten.

In the mid-1960s John Lozier had achieved senior status in the IFAC hierarchy as a member of the IFAC Executive Council and the way was paved for AACC to host the 1975 IFAC World Congress. In 1968 a provisional committee for IFAC'75 was established within the AACC. Because AACC itself had no experience organizing large technical meetings – recall that it was the member societies of AACC that hosted successive JACCs – a member society sponsor was needed for the Congress. The Instrument Society of America, one of the founding members of the AACC agreed to sponsor, on behalf of the AACC, the 6th IFAC World Congress to be held at MIT and Harvard in Cambridge, Massachusetts. The Chairman of the National Organizing Committee (NOC) was Nathan Cohn, Executive Vice President of Leeds and Northrup, a major instrument company in the US, and friend of a number of the former AACC officers, all of whom had industrial backgrounds as noted earlier. With his industrial contacts Nathan Cohn was an ideal candidate for this task. The NOC consisted of control engineers from industry and local arrangements were handled by Larry Ho, Mike Athans, and George Newton from Harvard and MIT.

The JACC series of annual meetings began by reflecting a reasonable balance between theoretical and practice-oriented contributions in the 1960s and early 1970s. Although it is only speculation, this balance may have partly been realized by the strong presence of industry based AACC leaders during the early years of the meeting series. Because of the early agreements among the member societies of AACC, the JACCs tended to be the most important control engineering meetings in the US each year. Member societies had agreed not to hold independent control meetings that could compete with the JACCs. Attendance and interest from foreign authors was modest and growing but the original idea of having the JACC being the only control meeting of the member societies was rather quickly becoming untenable. In many of the member societies, sessions on control engineering were often present in larger scope conferences. Over time the planned exclusivity of the JACC caused all sorts of havoc for the member societies. Problems of date conflicts with other meetings, including IFAC conferences in the US were common. Although there was a planning function for JACCs envisioned in the Bylaws of AACC, and guidelines were developed, rotating responsibility every year among the sponsoring members of AACC led to problems that were not to be rectified until the early 1980s. The JACCs suffered from lack of continuity among organizing teams and a growing unhappiness with university style "hotel" rooms in often remote locations. There was a growing sense that the "national American control meeting of the year" should be a bit more elegant, more centrally organized in a consistent style, less of a burden to single societies each year, more poised for growth, and more recognizable as a continuing annual event with a consistent image, more stable attendance, and ever higher quality papers and presentation in professional surroundings. In the midst of all of this the AACC prepared to host the 6th IFAC World Congress in 1975 in Cambridge. There was no JACC held that year.

Thus during the mid-1970s the focus of AACC was on the organization of the IFAC Congress and the following JACCs in succeeding years which were still plagued by the difficulties mentioned above. JACC attendance was not strong, and even with a substantial JACC Operating Manual in existence, the whole process of having an annual meeting was neither smooth nor financially stable. Occasionally one of the annual sponsors would simply not follow the agreed upon rules about meeting dates or other details that deviated from that society's standard operating procedures for their other meetings. John Zaborszky, a Professor at Washington University in St. Louis was moving toward the AACC Presidency and committed himself to resolve this long standing problem with the JACC around the time of his two-year AACC Presidential term in 1980-1981. For several years prior to the emergence of the American Control Conference, JACC attendee surveys were taken and analyzed, old ideas about rotational hosting, inconsistent image and conflicts were removed from new operating principles. One of the key principles of the new annual meeting, the American Control Conference (ACC), was that there was to be an AACC standing committee for the ACCs with rolling membership including individuals who were involved in organizing contiguous ACCs. Another fundamental principle was that the AACC itself would have financial responsibility for all ACCs and that the surplus from each ACC was to be used for AACC expenses plus a distribution by formula back to member societies. The formula included weightings that benefitted member societies according to the number of ACC papers accepted and number of attendees from each society. So it was that in 1982 the first ACC was held in Arlington, Virginia, a suburb of Washington, DC. The IEEE accepted permanent responsibility for post conference ACC proceedings, an arrangement that has evolved over time but in various forms has continued to this day and has been an important source of income to the AACC and its member societies.

In the 1970s the process control industries, a major sector for automation, were not benefitting from rapid advances in control and computer technology. This led the ACC to plan and execute a national industry wide study of automation with the potential for near-term implementation. A subcommittee of AACC was established called the Automation Research Council which was designed to manage research funding to determine research needed to make qualitative improvements in automation in industry. This ambitious project was led by a former AACC President, Professor Ted Williams of Purdue University. It was to be the only time the AACC was actively involved in a government funded project. There were additional attempts to obtain federal support for research planning studies but the AACC was not a particularly good vehicle for obtaining such support. Even in those days the federal government was not enthusiastic to fund industrial groups or even industrial/academic consortia since the National Science Foundation was a research funding agency rather than a research planning funding agency. Many of the individuals in AACC who were working in universities had individual research grants from the NSF, but these were not related to AACC activities.

After the transition from the JACC to the ACC in the early 1980s AACC leadership was drawn more from academia than industry. In the United States there tended to be less support for professional society activities from American industry; academia moved into the void thus created. Unfortunately this characteristic has persisted into the 21st century. It can be argued that this shift reflected more emphasis by US companies on short term planning and growing emphasis on short term goals driven in part by financial market pressures and globalization. However, the research community in the control field responded well to the new style of the ACCs and the conference, although somewhat more research oriented than may be wished by the development and manufacturing communities, have thrived for several decades up to now.

As noted, Jack Lozier's leadership within IFAC occurred from the late 1960s through his Presidency from 1972 to 1975. In the middle 1960s IFAC had a few technical committees including Theory, Applications, Education, Terminology. In addition each of these committees had many subcommittees on various contemporary topics. It became obvious to Lozier that IFACs growth depended on the success of such committees and their expansion and leadership. It is hard from today's perspective to realize in those days how important terminology and standards were to this fledgling professional field of control and systems. Rather than continue to try to force all control technical interests into so few committees with numerous subgroupings (task forces, subcommittees, working groups), it was useful to convert many of the subgroups into technical committees in their own right. By the end of his presidency there were between 15 and 20 IFAC Technical Committees. The presence of so many TCs in IFAC influenced the AACC as well, and the number of AACC technical committees also expanded. In part, this expansion introduced many more middle level international technical leadership openings for Americans and, of course, for all the other IFAC member states.

AACC/IFAC foundation building

Following Lozier's service on the IFAC Council and as IFAC President, William Miller, an American technical marketing executive for General Electric's steel mill automation department took on the senior leadership role from the United States within IFAC. He had extensive industrial contacts in many IFAC countries and by virtue of all this experience was well informed and well recognized within the IFAC countries. He had served as chairman of several IFAC committees including as Chairman of the powerful IFAC Advisory Committee (later to become the IFAC Technical Board) and eventually as an IFAC Vice President. By the early 1980s the other American who was taking a leading role in the US-IFAC relationship was Professor Stephen Kahne. Kahne already had more than a decade of IFAC experience in committee leadership roles and in publications including creation and leadership of the IFAC Publications Managing Board (PUMB), a joint publications venture between IFAC and Pergamon Press (and after mergers, Elsevier Science, Ltd.). He was in line to be President of the IEEE Control Systems Society in 1981 and thus a Director of the AACC at that time.

Americans had always been part of the IFAC family since the beginning, and as the Federation matured they realized that certain symbolic traditions were valuable for a stable and growing organization. It was Nat Cohn, IFAC'75 NOC Chairman who developed the idea of creating an original banner to symbolize each IFAC Congress. The collection of these would be prominently displayed at each Congress venue. Of course at the time of IFAC75 there was not a collection for previous Congresses. Cohn and his colleagues from AACC designed and produced one banner for each of the previous five Congresses as well as one for IFAC75. That tradition has continued to this day. The tradition, started by the AACC in 1975, is for each upcoming Congress NOC to create its own banner (all the same overall size with an image appropriate for the Congress venue) and unveil it at the Closing Ceremony of the previous Congress. The complete collection of banners, growing by one each triennium, appears at each Congress site as part of ceremonial displays. At the IFAC Congress in Seoul, South Korea in 2008, the Korean NMO distributed a booklet "Book of Banners" that shows the entire collection of 17 banners up to that time.

Just before IFAC'75, another AACC contribution was introduced into IFAC traditions when Irena Kahne, artist wife of Stephen Kahne, created and donated to IFAC an artistic tapestry displaying the IFAC logo. This became the official IFAC Presidential tapestry. It is presented by the outgoing to the incoming IFAC President as part of the transfer of office ceremony at the closing session of each Congress. It remains in the office or home of the current President for three years until passed to the next President during the next Congress. Other symbolic objects have been created by other NMOs and are now part of IFACs continuing transitions.

Once the 1975 Congress was behind them, AACC took on two pressing problems. One of these was the transition from JACC to ACC and the second was a new and stable structure for the AACC Secretariat. Following one-man operations for the first 20 or so years of AACC existence, the AACC Secretariat had briefly been housed at the Instrument Society of America (ISA) headquarters. The institutionalized secretariat operation at the ISA could not keep up with the growing load of responsibilities. Numerous IFAC related correspondence was being overlooked and the AACC/IFAC relationship was becoming somewhat strained. The volunteer AACC Secretary in the early 1980s was Marion (Bud) Keyes from the Bailey Controls Company. Keyes was promoted to President and General Manager of Bailey and did not have time to continue as AACC Secretary. Bill Miller was approaching retirement at General Electric, had extensive knowledge of IFAC and of AACC and was prepared to take on the AACC Secretariat function. His appointment as AACC Secretary, which would turn out to be nine years long, set the stage for AACC to see success for its Newsletter, its new annual conference, its finances, and the gradual modernization into computerized secretarial operations. While AACC needed to continually update its data processing technology there was also a need to try to remain compatible with the IFAC Secretariat as it also was modernizing its office operations. There were frequent debates about Mac vs. PC office computer setups between IFAC's Laxenburg staff and the new AACC office run by Bill Miller. Teletype machines were being replaced by facsimile technology. Electronic records were being created in various incompatible formats and these were changing at different speeds around the world. Miller had developed some expertise in this new office automation and became a principal advisor to the IFAC Secretariat on these matters. He was an advocate of the Mac style of office automation. There were friendly differences between the American approach and the European approach.

Preparing for a second World Congress in the US

These transitions renewed an IFAC leadership role for the US with Miller, then transitioning to Kahne, in leading IFAC positions going forward. During Miller's term as AACC Secretary (1982-1991) there were 35 IFAC technical events in the United States. To support the coming ACC in 1982 and beyond, a new AACC Newsletter was being designed and implemented. In addition, the first discussions were taking place within AACC to invite IFAC to hold its World Congress in the US in the mid-1990s. This would require that an American, to be IFAC President in the future, would need to be identified a decade ahead.

At first the AACC delegated to specific US institutions the authority to host IFAC technical meetings in the US. This led to a somewhat disorganized collection of IFAC conferences each with its own conference proceedings, each prepared by a different printing company and later available for purchase from different local distributors. The hosts were different local units, typically universities. AACC formally authorized each meeting and ensured that basic IFAC rules were followed. As IFAC publications policies evolved and as the JACC/ACC transition progressed, AACC's role changed. Since the middle 1980s AACC gives formal national approval of a meeting recommended by an IFAC technical committee to ensure that IFAC policies are followed by the US organizers. This approval includes a financial underwriting commitment for the event in case of financial difficulties. In any case, ultimately it has always IFAC's decision whether or not to agree to the date, place, and proposed content of the event.

There is value in having active specialists from an NMO as members of the various technical committees of IFAC and participating in decisions made by those committees about topics, venues, and dates of such IFAC events. All IFAC technical meetings are the responsibility of the appropriate IFAC Technical Committee and IFAC's rules require that the International Program Committee (IPC) for each IFAC technical event be truly international. There was an early tendency to only use national technical experts on the IPC for IFAC events held in a particular country. The requirement for a truly international team of experts to frame the technical program of these events was firmed up during IFAC's evolution. This ensured that some Americans were almost always on IPCs for all IFAC meetings and represented still another way that new international opportunities for leadership were available to the AACC community. At the same time, the annual ACC Program Committees grew into truly international groups of technical experts to shape the annual ACC programs. Workshops and Tutorials at the ACCs were a popular feature on the meetings and an international group of lecturers became a standard feature of the meetings, often serving as plenary lecturers or workshop organizers. Thus by the middle 1980s the American Control Conference was really an international meeting.

In 1991 Lennart Ljung was an IFAC Vice President and Chairman of the IFAC Technical Board. He and the IFAC Council were eager to keep US and IFAC interests aligned and to ensure that the major US control conference (the ACC) was operated and scheduled in a manner that would facilitate strong international participation. The suggestion from both sides was that some sort of relationship be established to accomplish that. Thus it was that since 1991 the ACCs have been "affiliated with" IFAC and the idea of IFAC regional conferences grew to include European, and Asian IFAC regional conferences. Once again the American-IFAC relationship proved to be a creative force within the international community.

After the Boston/Cambridge IFAC Congress, AACC arranged occasional special technical visits by American scholars and industry control engineers. This is one way for the IFAC community to bring control and automation ideas to countries that can benefit from this technology. In the 1970s a South American lecture tour was arranged by Purdue University's Ted Williams. Americans, under the auspices of the AACC and its members went abroad in small groups on teaching and technical tours. In 1981, the IEEE Control Systems Society led a multi-city technical tour of China with many participants from the AACC technical community. An Eastern European technical tour was led by Bill Miller to several countries in the mid-1980s. Another such study visit was a Chinese trip in the late 1980s. In each case AACC facilitated the arrangements through its contacts with other IFAC NMOs in the visited countries. Such institutional help was important in those days because there remained numerous government impediments to free travel and interchange of technical ideas.

With the 1986 IFAC commitment to hold its World Congress in the US in 1996 and the several previous years of preparation leading to that decision, many AACC activities began to focus on IFAC and the AACC-IFAC relationship. Kahne had always believed that the American control community should be better informed about IFAC and the American role in it. In 1987 he initiated "Global Concerns" a regular column in the AACC Newsletter which conveyed to the American audience insights into IFAC and other international issues of interest to the AACC. This regular column in the Newsletter has been authored by the contemporary US member of the IFAC Council up to the present time. In addition there were more opportunities for Americans to serve in technical leadership positions in IFAC.

As part of a strategic plan for IFAC, the structure of the IFAC Technical Board changed in 1993 to create more technical committees within IFAC. The IFAC TCs had previously developed a complicated structure of various task forces and sub committees to accomplish the technical work in their fields of interest. It was found that volunteers leading these efforts had more success in getting the support needed for their volunteer tasks if they were heading Technical Committee rather than sub-units of TCs. Under the leadership of Lennart Ljung (IFAC Technical Board chair 1991-1993), a new IFAC Technical Board structure was initiated. During the next two triennia, Vladimir Kucera (IFAC Technical Board Chair following Ljung) and his vice chairs (Mike Rabins and Mike Masten, from the US), refined the new Technical Board into the operational structure used today. The number of IFAC TCs jumped from about 15 to about 40. They are organized into Coordinating Committees and the Chairs of these CCs became members of the IFAC Technical Board. These senior technical leadership positions provided opportunities for Americans and other NMO members to serve in higher level IFAC positions. Names of Americans who have served in all these IFAC leadership roles are in an appendix to this document.

Key IFAC96 Congress leaders were appointed by the AACC. Dr. Harold Sorenson, Senior Vice President and General Manager of the MITRE Corporation was appointed NOC Chairman for the Congress. Professor Jose Cruz at UC-Irvine then Ohio State University Engineering Dean, was appointed IPC Chairman, and Professor David Auslander at UC-Berkeley was the Conference Manager. As part of the early planning, the IEEE underwrote financial responsibility for the Congress, a guarantee that was never used because of the eventual success of the Congress.

At the same time, annual ACCs were handled with professional skill each year by a growing cadre of volunteers. The strength of each program and level of attendance grew almost monotonically with each event. For 1996, the ACC was replaced by the IFAC Congress in San Francisco. In order to gain experience with the San Francisco conference management community, the 1993 ACC was also held in San Francisco, a dry run for the 1996 Congress.

During this period from the mid 1980s to the mid 1990s, AACC became more active with new awards being created, not only for the AACC but also for IFAC. Harold Chestnut's family approached Steve Kahne in 1986 with an offer to fund an IFAC prize for the best textbook in control. As noted earlier in this narrative, it was Harold Chestnut's earliest textbook that was instrumental in his selection as the first IFAC President in the late 1950s. The family thought it would be appropriate if they contributed to the recognition of authors of outstanding control textbooks. It was agreed by IFAC to use these funds for a textbook prize and at Kahne's recommendation, they agreed that the Chestnut name would not be used for this prize while Harold Chestnut was still living. The first of these triennial awards was made in 1987 and after Harold died in 2001, this IFAC prize was renamed the Harold Chestnut Control Engineering Textbook Prize. Based on his experience as the chair of the IFAC Quazza Medal Committee Petar Kokotovic suggested a new IFAC award to recognize important achievements in control engineering practice to honor Nathaniel Nichols. With strong support of Steve Kahne, AACC agreed and worked with IFAC to produce IFAC's Nathaniel B. Nichols Medal which was awarded for the first time at the 1996 IFAC Congress in San Francisco to Professor Jurgen Ackermann. Nick Nichols was in the audience for the presentation. AACC underwrote the startup costs of the award and IFAC has supported it in the long term. The next three triennial IFAC Nichols Medals went to three outstanding American control experts from US industry and subsequently outstanding industrial leaders in control from throughout the world have been so recognized.

By the late 1990s the ACC regularly used electronic media for producing its Proceedings. The technology used for proceedings changed from CDs, then DVDs and some conferences now use flash drives. Various attempts to encourage industrial participation in the ACC have been tried, with modest success. Pre-conference workshops as part of the ACC program have been in place since the early 1980s. Special review processes for industrial papers have been tried. In addition, experiments have been tried using industrial practice invited sessions, daily registration fees to attract local industrial specialists, special topic panel discussions, jointly sponsored technical sessions with industrial groups, have come and gone over time.

New century

In the US questions about security and intelligence for safety of industrial processes led to the creation of a Process Control Security Forum (PCSF) at the start of the 21st century. The lead agency in the US government was the newly created Department of Homeland Security. Its purpose was to share information about security of process industries that were susceptible to terror threats. Control systems are at the heart of many of these industrial sectors including electric power, petrochemical companies, pharmaceutical manufacturing, and public works. There are many barriers to free exchange of information in this environment and it is uncomfortable for AACC play an active role. However, the technologies represented by the AACC member organizations play key roles in all these industries and a common base of science and engineering practice recommended that AACC participate in this PCSF. The national security implications of this topic finally led to its demise outside of the intelligence community and so AACC's role was minimal but it did remind us of the relevance of the control sciences to a wide range of safety and security matters facing the United States.

For the past ten years the AACC in cooperation with other societies has created an Ideas and Technology Control Systems workshop for middle and high school teachers and students. These workshops are held twice a year, one of which coincides with the time and venue of the ACC. During the last decade the workshops were presented to over 3,000 students and teachers in Baltimore, Chicago, Denver, Hawaii, Las Vegas, New Orleans, Portland, San Diego, Seattle, and St. Louis.

The activity strives to bring control system concepts and technologies to the attention of high school and middle school students and teachers. It is explained that control is used in many common devices and systems, such as computer hard drives, VCRs, automobiles, and aircraft, but it is usually hidden from view. It is understood that the longevity of the control field which spans science, technology, engineering and mathematics (STEM), depends on its continuous success in attracting the most gifted young people to the profession. Furthermore, early exposure is a key to achieving that goal. This pioneering effort brings control systems to middle and high school students and their teachers. The goal of these outreach efforts is to promote an increased awareness among students and teachers of the importance and cross-disciplinary nature of control and systems technology.

Before NSF was concerned with K-12 education our control community had the idea that high school teachers and their students should be made aware of and become involved in basic ideas of control theory. The idea was that education is at all levels an inclusive process. It should integrate scholarship, teaching, and learning both horizontally and vertically. Professor Bozenna Pasik-Duncan from the University of Kansas has spear-headed the effort since its inception.

AACC and its partners have developed a model that has been followed by other organizations and societies. We established a sustainable outreach partnership among our control communities and the school districts at the places where our major conferences are held.

The workshop activities include presentations by control systems experts from our technical community, informal discussions, and the opportunity for teachers to meet passionate researchers and educators from academia and industry. The talks are designed to be educational, inspirational and entertaining, showing the excitement of being an engineer.

In addition discussions and presentations of "Plain Talks" were initiated. This important educational activity was closely related to the outreach efforts described above. The goal has been to develop short excellent presentations not only for teachers and students, but also for other non-control engineering communities.

AACC is proud of its history of facilitating a strong control presence in the US and continuing contributions to the international scene through IFAC. The current team of American leaders remains committed to providing a structure for constructive exchange of ideas across all engineering disciplines and to ensure close collaboration with the world-wide control community.