Approximately 12,000 letters to Allan Nevins from various correspondents including James Truslow Adams, Franklin Delano Roosevelt, Harry S. Truman, Willa Cather, Frances Folsom Cleveland, Van Wyck Brooks, Robert Frost, Newton D. Baker, Archibald MacLeish, John D. Rockefeller, Jr., Carl Sandburg, and Henry Wallace; notes and typescripts for Nevins' books including Emergence of Lincoln, The Ordeal of Democracy, Rockefeller, and History and Historians, with notes by editor Ray A. Billington; miscellaneous transcripts, clippings, newspapers, and photographs. Also, autograph letters and manuscripts by presidents, Civil War figures, financiers, politicians, and authors. There are also the Brand Whitlock World War I Diaries and letters to him by such people as Herbert Hoover, Gen. John J. Pershing, and others.

Materials relating to the American Civil War and the men who fought in it, chiefly of the Union Army.

John Jay II was a graduate of Columbia college and an abolitionist. This collection includes letters, legal and financial documents, newspaper clippings, writings, photographs, circulars, and pamphlets.

Contemporary engravings, lithographs, carte-de-visite photographs, and memorabilia; 20th century drawings and reproductions of portraits of Lincoln, his family, and his contemporaries. Among the portraits of Lincoln are a charcoal sketch by the sculptor Gutzon Borglum, lithographs by Currier and Ives, photographs by Mathew Brady and his studio. Memorabilia in the collection include bookends and sculptures, a dinner plate, a carved plaque, a reproduction of a death mask, a mourning ribbon, silk commemorative badges, and a hair ornament worn by Mrs Lincoln, in a leather-covered trinket box with the President's initials on it.

This collection is primarily concerned with Prof. James Renwick and his professional correspondence and papers, both as Professor of Natural Philosophy (Physics) at Columbia College and as a leading engineer. Many certificates of membership in honorary societies are included. There are letters from Washington Irving (1783-1859) to Prof. Renwick and to his mother, Jane Jeffrey Renwick, pertaining to contemporary events and Irving's own activities. The letters to Mrs. Renwick are about the travels and experiences of Irving and Renwick abroad. The collection also covers the affairs of the Prof. Renwick's grandfather, including documents concerning his land grants in New York State, and those of James Armstrong Renwick, including his valedictory address at Columbia College in 1876 and his class reunion in 1916. There are many legal documents, letters, and manuscripts of various members of the Renwick and Brevoort families; among these are Prof. Renwick's notes on his family genealogy and a memoir of Jane Jeffrey Renwick. Correspondents include Clement Clarke Moore, John A. Dix, Martin Van Buren, Secretary of State John Forsyth, and Secretary of the Navy James K. Paulding. There is one letter from Sir Edward Sabine (1788-1883), President of the Royal Society, giving his views on the American Civil War.

Proofs, photographs, photostatic copies, and other printed materials of Roscoe. Included are proofs and illustrative materials for his book The Web Of Conspiracy; The Complete Story Of The Men Who Murdered Abraham Lincoln, and a printed copy of his book, Only In New England, a book of crime fiction.

Correspondence, manuscripts, notes, memoranda, notebooks, notecards, proofs, photographs, microfilms, and printed materials. The Papers include the manuscript research materials and correspondence for each of his books except his biography of Theodore Dreiser. Among the correspondents are William Benton, Bruce Catton, Carey McWilliams, Mrs. Fremont Older (Cora Miranda Baggerly Older), and Thornton Wilder.