Correspondence, articles, memoranda, and other papers relating to Belknap's naval career including his duty in the barrier forts at Canton (Guangzhou.), China, in the 1850s; combat duty in the Civil War; a tour of duty in Hawaii; and his command of the Asiatic Fleet. Subjects include hydrography; oceanography; old sea stories; social, economic, and political questions; and Belknap family affairs and genealogy. Correspondents include Daniel Ammen, John M. Brooke, Caspar F. Goodrich, Samuel W. Lowell, Francis Asbury Roe, George Collier Remey, and John A. Riddle.