This module offers documentation on the growth, transformation, successes and failures of one of the important American social movements of the nineteenth and twentieth centuries, the modern American labor movement. Four major national organizations are represented in substantial detail: the Knights of Labor, AFL, CIO, and AFL-CIO, with additional documentation on the United Mine Workers. Three of the collections come from the holdings of Catholic University of America: Papers of Terence V. Powderly and Papers of John W. Hayes, focusing on the Knights of Labor, and Papers of John Mitchell, focusing on the United Mine Workers and the AFL. Other collections in this module come from the holdings of Wisconsin Historical Society and the University of Maryland.