The collection consists primarily of letters received by Mather during the years he was a professor in the art and archaeology department at Princeton (1910-1933) and the first director of the Museum of Historic Art (1922-1946), now the Princeton University Art Museum. Correspondents include such colleagues and friends as John Truslow Adams, Irving Babbitt, Bernard Berenson, Van Wyck Brooks, Royal Cortissoz, Arthur Hazard Dakin, Henry Holt, Clare Leighton, Allan Marquand, Paul Elmer More, Lewis Mumford, and Hans Tietze. The collection includes a unique war item, a letter sent by Mather to Bernard Berenson in England in 1941 that was intercepted and returned by German censors. Also present are copies of "A Private Life," the unpublished autobiography of Mather's father, Frank Jewett Mather (1835-1929), and a few photographs of Mather.

Additions to the collection include correspondence between Mather and Abris and David Silberman (1828-1848) of E. and A. Silberman Galleries in New York City regarding acquiring artwork for the Art Museum, and a manuscript essay on Herman Melville.

The following standard abbreviations, or their variations, are used to identify materials in this collection: AMsS = autograph manuscript signed and TMsS = typed manuscript signed.