Communism is a political and economic system based on the belief that all people should share equally in society's resources and rewards. In the United States between 1937 and 1950, communists played an important role in the labor movement. They organized workers and fought for better wages, shorter workdays, and safer working conditions. Many communists also believed workers should have more control over their own lives and that racism, sexism and inequality should be ended. This meant they were often in the forefront of struggles for social and economic justice.