In the late 19th century, the American economy transformed from a predominately agricultural to an industrial one, with increasing numbers of wage workers laboring in factories, mines, and on railroads. Workers organized and struck for higher wages, safer conditions, and shorter hours. Employers responded with lockouts, the hiring of replacement of workers, and legal action. Violence was common.

In the early 20th century, workers, businesses, and government all tried to adapt to an economy that was becoming increasingly urban and industrial. The Progressive Era saw an upsurge of labor unrest, as well as proposals and laws to alleviate the worst abuses of industrial capitalism. Additional proposals were put forward during the 1920s, but fewer were enacted.

The Great Depression was a time of poverty and unemployment, but World War II expanded economic opportunities, especially for women and African Americans. Depression and war both brought clashes between business and labor that resulted in new Federal Government regulations and laws, and an upsurge in union membership.

After World War II, the United States experienced a dramatic economic expansion. Workers’ incomes rose, and prosperity became more widespread. The growth of organized labor peaked, but after a wave of postwar strikes, new laws and a hostile political environment made organizing employees more difficult, especially after the mid-1950s.

The African American civil rights movement brought about anti-discriminatory legal protections for blacks and inspired movements for civil rights among other groups. In the workplace, activism brought protections for individuals and increased government regulation. These directions expanded until the later 1970s with the renewed enthusiasm for free market solutions and deregulation.