Alexander Buel Trowbridge was born on December 12, 1929, in Englewood, New Jersey. Trowbridge attended Philips Academy in Andover, Massachusetts, and graduated in 1947.

After World War II, he volunteered to help with the reconstruction efforts in Western Europe. He also worked as a member of the International Intern Program of the United Nations headquarters in Lake Success, New York, in 1948. In 1950, Trowbridge served as an intern with Congressman Franklin D. Roosevelt Jr. The following year, he attended Princeton University and earned his bachelor's degree. Following graduation, he was hired by the Central Intelligence Agency and enlisted in the Marine Corps, serving during the Korean War with the First Division.

In 1954, Trwobridge went to work for the California Texas Oil Company as a marketing assistant for petroleum products. He remained with the firm until 1958, when he went to work for Esso Standard Oil in Cuba. In 1961, Trowbridge moved to Puerto Rico and became president and division manager of Esso Standard Oil.

President Johnson tapped Trowbridge to be the assistant secretary of commerce in May 1965. Trowbridge became acting secretary of commerce on January 18, 1967, and began his tenure as head of the department in June 1967. While serving in the Johnson cabinet, Trowbridge supported a merger with the Department of Labor and organized the Office of Foreign Direct Investment in order to curb a deficit in the balance of payments.

Trowbridge left his cabinet post on March 1, 1968, and became president of American Management Association two months later. Trowbridge went on to become vice chairman of Allied Chemical Corp. (1976-1980) and president of the National Association of Manufacturers (1980-1990). He then founded Trowbridge Partners, Inc., and currently sits on the board of several corporations.