"A unique archive of over 60,000 letters, diaries, pamphlets, printed books, newspapers, photographs, and ephemera that document the political, social, and economic history of the United States" (website homepage). The collection is searchable by keyword and can be limited by era, including "National Expansion and Reform, 1815-1860".
*Access available through the 2016 edition.
Published annually since 1972, each of the 38 volumes contains approximately one hundred primary source documents covering the most significant events of the year, including presidential speeches, international agreements, Supreme Court decisions, government reports, scientific findings, and cultural discussions.
Prelinger Archives is a collection of over 60,000 "ephemeral" (advertising, educational, industrial, and amateur) films. In 2002, the film collection was acquired by the Library of Congress, Motion Picture, Broadcasting and Recorded Sound Division.