The Library of the U.S. Department of Labor is one of the oldest Cabinet-level libraries. Historically, it ranks among the most important. Large segments of its collection comprise unique holdings - unique either in their nature and content or in the length and completeness of their coverage - which document the economic and social history of the United States, including the history of labor, labor unions and the growth and development of the labor movement in a national and world context. Apart from information about the library's holdings this site provides access to the online catalog.