The McCormick Library has several collections that contain correspondence, diaries, and other materials related to the Civil War era. Some materials describe the experiences of soldiers during the war, or who served in the territories; others document the “home front” trials and anxieties, and some provide reflections or analysis after the war.

Joseph Bartlett Dorr (1825-1865), left the management of the Dubuque Herald to recruit soldiers for the 12 th Regiment of the Iowa Volunteers in 1861.The Dorr Collection consists of manuscripts, documents, journal entries, and family correspondence written between 1837 and 1902.

Collection consists of the papers of Sherwin Warren King from his service as a sergeant in Company K, 42nd Regiment of the Illinois Volunteers during the American Civil War, as well as some papers from King's family and relatives. Collection dates from 1861 to 1942.

Correspondence, research notes, mapas, proofs, and reviews of McCormick's book Ulysses S. Grant (New York and London: D. Appleton-Century, Inc., 1934; also New York: Bond-Wheelwright, 1950).