David Chambers Mearns (December 31, 1899 – May 21, 1981) was a librarian and scholar of Abraham Lincoln.

He held multiple positions at the Library of Congress over 58 years of service, including director of the reference department, chief of the manuscript division, and Chair of American History.

[1] David Chambers Mearns was born December 31, 1899, in Washington, D.C.[2] He was a student at St. Albans School beginning in 1914, graduating in 1916.

[3] He continued writing about the history of the Library, including Herbert Putnam, 1861-1955 : a memorial tribute in 1956.

[3] Under his direction, the Library began the National Union Catalog of Manuscript Collections program, providing cataloging for archival and manuscript collections in archives and historical societies across the United States.

More than anything else, he represented the Library of Congress to a world of historians, bookpeople, the working press, and the public at large.The papers of Abraham Lincoln were collected and organized by his son Robert Todd Lincoln, who deeded the collection to the Library of Congress in 1923.

[9] Professor James I. Robertson Jr., director of the American Civil War Centennial Commission, contacted Mearns to research what those ceremonies had entailed.

[9] Using flashlights because the Library's timed lights would not operate after business hours, they retrieved issues of Frank Leslie's Illustrated Newspaper and Harper's Weekly, which gave elaborate details about Lincoln's funeral.