The American Memory collections contain many references to the Louisiana Purchase in various formats—including photographs, prints, maps, songs, and oral histories. An American Time Capsule: Three Centuries of Broadsides and Other Printed Ephemera includes broadsides, leaflets, and pamphlets relating to the Louisiana Purchase.
A Century of Lawmaking for a New Nation: U.S. Congressional Documents and Debates, 1774-1875 includes many documents about the Louisiana Purchase and the newly acquired lands.
The Louisiana Purchase: Legislative Timeline 1802-1807 explores the role of Congress in the Louisiana Purchase from 1802 to 1807, including ratification of the treaty, establishment of a territorial government, confrontation with Spain over boundary issues, and its limited role in the Lewis and Clark Expedition.
The Nineteenth Century in Print: The Making of America in Books and Periodicals includes articles describing the history of the Louisiana Purchase.
Primary Documents in American History: Louisiana Purchase provides access to the text of the Louisiana Purchase Treaty, links to digital material associated with the treaty, and bibliographies for both adult and young readers.
Rivers, Edens, Empire - Lewis & Clark and the Revealing of America, an online exhibition that contains maps, images and documents concerning the Lewis and Clark Expedition and the Louisiana Purchase.
The Thomas Jefferson Papers contain many papers relating to the Louisiana Purchase which occurred during Jefferson’s administration.