John Langdon Sibley
Sibley was the son of Dr. Jonathan Sibley and his wife, née Persis Morse. He received his undergraduate education from Harvard and then studied at Harvard Divinity School. From 1829-1833 he was a pastor in Stow, Massachusetts. He then went to Cambridge, Massachusetts where he worked as a magazine editor. When Harvard's first purpose-built library building, Gore Hall, was opened in 1841 he was appointed the assistant librarian under Thaddeus William Harris. In 1856 when Harris died Sibley became the librarian of Harvard.
On 30 May 1866 Sibley married Charlotte Augusta Langdon Cook, at Sommerville, Massachusetts. 
Sibley oversaw both the physical and fiscal expansion of the Harvard Library. He also compiled the initial volumes of Sibley's Harvard Graduates (covering the Classes of 1642 to 1679) and bequeathed funds to the Massachusetts Historical Society for continuation of this project. Clifford K. Shipton published 14 more volumes (Classes of 1690 to 1771) and in 1999 an 18th volume appeared (1772 to 1774).
- Potter, Alfred Claghorn; Bolton, Charles Knowles (1897), The Librarians of Harvard College 1667-1877, Cambridge, Massachusetts: Library of Harvard University, p. 40, retrieved 15 December 2011
- Sibley, John Langdon, Sullivan, Brian A., ed., Sibley's private journal (1846-1882) (private journal), Boston, Massachusetts: Harvard University Archives, Harvard Library call number: HUG 1791.72.10, retrieved 15 December 2011