<human>: I'm trying to learn more about the history of the United States. Any suggestions on good sources of information?
<bot>: 
1. The Library of Congress is a great source for finding primary documents and other historical records related to US history.
2. The National Archives and Records Administration (NARA) has an extensive collection of government records, including presidential papers, congressional hearings, and military records.
3. Many universities and libraries offer online databases with digitized primary sources from the 19th century.