The Eli Whitney Papers consist of correspondence and business papers relating to Eli Whitney's invention and patenting of the cotton gin and to his subsequent development of a system to produce firearms employing interchangeable parts. The papers include drawings for machinery, land records relating to the acquisition of property for Whitney's factory site, patents and other documents relating to the protection of Whitney's inventions, and account books and other financial and legal records relating to business and investments. The papers also document the continuing manufacture of guns at Whitney's factory after his death in 1825, under the management of his estate and later of his son Eli Whitney. In addition, the papers include personal papers of Eli Whitney and other family members. The papers also include photocopies of documents relating to Eli Whitney located in other repositories including the Connecticut Historical Society, the Harvard College Library, the Massachusetts Historical Society, the National Archives, the New Haven Colony Historical Society, and the New York Historical Society. Additional photocopies of Whitney material from the Baldwin Family Papers, the Blake Family Papers, the Hillhouse Family Papers, and the Josiah Whitney Papers in the Manuscripts and Archives Department are also included in the papers.