In 1943 the PWOC was officially chartered as the UPWA. In October 1943, the PWOC officially became the UPWA. Its headquarters was located in Chicago. The UPWA's rival union was the Amalgamated Meat Cutters and Butcher Workmen, an older AFL craft union. The Amalgamated Meat Cutters and Butcher Workmen was a conservative union, whereas the UPWA was a more radical, left wing union. In the 1940s, the UPWA won nationwide contracts with companies including all members of the "Big Four" of meatpacking: Armour, Swift, Wilson, and Cudahy. Contracts for members of the UPWA were generally more stable than those of the AMCBW. They also offered better working conditions. Outside of labor rights, the UPWA was a major driving force behind many community reform movements, such as the "Back of the Yards Neighborhood Council" founded in Chicago in 1939. The UPWA was committed to interracial cooperation, and starting in 1949 the union began pursuing anti-discrimination activities. In 1950, the UPWA created an Anti-Discrimination Department, dedicated to ending racial discrimination in meat packing plants and working against segregation in local communities. The three goals of this department were: to break down all-white plants, to end discriminatory practice in communities, and to facilitate work with other civil-rights community organizations, such as the NAACP. In the 1950s and 1960s, the UPWA was at the forefront of union support for the Civil Rights Movement and was a strong ally of Martin Luther King Jr. Historians regard the UPWA's civil rights activity as a prime example of social unionism. During the 1950s, the UPWA made workplace equality for women a central goal. Though the idea never gained as much prominence as the fight for racial equality, the UPWA was still able to make a difference for women in the workplace. Ending men's and women's wage differentials was the focus of the UPWA. Ending discrimination against pregnant women workers was another important focus. As a result of the UPWA's work, pregnant women were able to receive up to one full year of unpaid leave and up to eight weeks of half-paid leave, under the union's sick-leave provisions. The meatpacking industry restructured in the post World War II years. The "Big Four" lost their dominance, and a new "Big Three" took power. IBP, ConAgra, and Cargill were the companies that made up the "Big Three."