Bill of sale between George C. McNeill and James Root and Willard Leonard for the slaves; Nancy and her two children, Austine and Henry; and Leah, 1838

The Henry P. Slaughter collection consists of materials collected by Henry P. Slaughter which emphasize the early history of African Americans in the United States. It contains materials which date from 1667 to 1964, however, the bulk of the material spans from 1792 to 1959. The collection is composed mainly of slave papers and correspondence of African American leaders, abolitionists, and political figures of the nineteenth and early twentieth centuries. The materials include pamphlets, sermons, speeches, reports, correspondence, and legal documents.

The Collected historical documents are divided into eight subseries. These include People, Legal documents, Broadsides, Masonic organizations, Music, Photographs and political cartoons, Unemployed citizens' organizations, and Henry P. Slaughter, divided into Catalogs, Correspondence, and Personal items.

The People subseries includes the correspondence and autographs of a wide variety of historical figures. Most of the files contain only one or a few letters of the person, however a few names have a significant amount of correspondencee. Letters to and from John W. Phelps, Brigadier General of the 12th Connecticut Volunteers, document his efforts to organize and train Black regiments for the Union forces. Correspondence while Phelps was camped at Camp Parapet, Louisiana following the fall of New Orleans explain the plight of a large number of Blacks, many of them freedmen, coming into camp seeking food and shelter or protection from vengeful whites. This series also contains letters between Phelps and Thomas Webster, member of the Supervisory Committee for Recruiting Colored Regiments (Philadelphia), detailing the Committee's efforts including fund raising for schools for Black children in Louisiana, and the establishment of a training school for officers to command the Black regiments. Several letters from the late 1860s and 1870s indicate that Phelps carried his concern and activities on behalf of the Black man into the Reconstruction era.

The Haiti Papers relate to the Haitian revolution from circa 1791-1804. Includes correspondence of Toussaint L'Ouverture, Jean-Jacques Dessalines, Henri Christophe, Alexandre Petion, Jean Pierre Boyer, which generally concern military details or safe-conduct for individuals. Of particular note is a letter by L'Ouverture of his feelings for Saint Dominque, for France, and for the coming negotiations with the French agent Philippe Roume; and a letter from a Haitian agent sent by L'Ouverture to the United States to reestablish trade following the conquest of Saint Dominque.

The correspondence of Frederick Douglass, Sr. reflects his activities as a lecturer against slavery, his feeling that employment open to African Americans was rooted in servility, Douglass's political associations and appointments, and his selection as Minister to Haiti (1889).

The correspondence of Frederick Douglass, Jr. is addressed to Magnus L. Robinson and discusses the two men's financial problems, the progress of African Americans, Frederick Douglass, Sr.'s return from Haiti, and the 28th anniversary of the Emancipation Proclamation.

William Lloyd Garrison's early letters to Samuel J. May and Franklin B. Sanborn, discuss the American Anti-Slavery Society, the Liberator, an anti-slavery newspaper, and other figures associated with the anti-slavery movement. Post Civil War letters refer to a biography of Garrison and histories of the anti-slavery movement.

The correspondence of Wendell Phillips primarily discusses his lecture schedule with some references to his political philosophy, the annexation of Texas, the slavery question, and Judge Joseph Story of the United States Supreme Court.

The papers of Gerrit Smith document Smith's concern with the temperance and abolition movements, the Liberty Party, his theory of compensation for slave owners, and his antipathy to land monopoly. Also included in the collection are broadsides and printed circulars.

The Legal documents subseries, also known as the slavery papers, consists of records pertaining to slavery in the United States from 1667 to 1867. They include indentures, slave bills of sale, manumission papers, and contracts. Slave bills of sale mainly represent Bibb County, Georgia, with some from Florida, Kentucky, Missouri and Virginia. Additional materials include contracts for slave rentals during the antebellum years, and indenture or apprenticeship papers for freedmen.

Also of note is the extensive collection of sheet music, most of which is composed or arranged by Harry T. Burleigh and J. Rosamond Johnson. The publications of Masonic organizations, especially the Grand United Order of Odd Fellows, reflect Slaughter's own participation in the fraternal world. The catalogs from and correspondence with book dealers document the market at the time Slaughter was avidly building his collection.