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.

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.