The Textile Workers Union of America (TWUA) began in 1937 as the Textile Workers' Organizing Committee (TWOC) of the Congress of Industrial Organizations (CIO). By 1939 the committee's success in organizing workers, especially in New England, led to its becoming an independent CIO affiliate. World War II revived a foundering U.S. textile industry and put textile workers in an advantageous bargaining position. One of their first major victories was a contract with the American Woolen Company in Lawrence, Massachusetts. By 1942, the mills in a number of other New England cities were unionized and although the War brought a respite to confrontation, organizing continued. The TWUA eventually organized most of New England's textile workers, as well as 70,000 southern workers by the end of WWII. In 1945, the TWUA was also instrumental in obtaining a War Labor Board directive eliminating North-South differentials in cotton textile wage rates. The union became international when Canadian textile workers organized in 1945 under the guidance of TWUA.

After the War, the TWUA faced serious problems; national anti-labor legislation which included the Taft-Hartley Act was passed and competition from southern mills and those abroad caused a decline in New England's textile industry.

By 1976, the continued decline of the textile industry especially in New England made it advantageous for the TWUA to join forces with the Amalgamated Clothing Workers of America (ACWA) to form the Amalgamated Clothing & Textile Workers Union (ACTWU). .

In 1995, ACTWU merged with the ILGWU (International Ladies' Garment Workers' Union) to form Unite! (Union of Needletrades, Industrial and Textile Employees) with headquarters in New York City.