The Amalgamated Clothing Workers of America, the most significant union representing workers in the men's clothing industry, was founded in Chicago in 1914 as a breakaway movement from the United Garment Workers.
Under the leadership of Sidney Hillman, the ACWA grew rapidly. By the late 1920s the union had organized over 100,000 members in the major garment industry cities across the United States and Canada. The depression severely thinned its ranks, but by the mid-1930s, the union had regained sufficient organizational strength to become a leading player in the creation of the CIO.
Sidney Hillman became an influential figure in political circles and a key advisor to Franklin D. Roosevelt on labor and economic issues, serving on the board of the National Recovery Administration. During World War II, Hillman was named associate director of the Office of Production Management, which assisted in mobilizing the nation's resources for the war effort.
Hillman's death in 1946 was a significant blow to the ACWA. Though the union continued to grow under his successor, Jacob Potofsky, its influence in national political and labor affairs was diminished. In 1976, the union merged with the Textile Workers of America to become the Amalgamated Clothing and Textile Workers Union; In 1995 the ACTWU voted to merge with the International Ladies' Garment Workers' Union to form the Union of Needletrades, Industrial and Textile Employees (UNITE).