Harman records in the two diaries the day-to-day activities of a soldier, including meals, marches, a trip on a schooner, illnesses, skirmishes, and his income and expenses. The diaries span the dates December 21, 1861 to May 27, 1863, the day that he was killed in battle at Port Hudson, Louisiana.

The other papers are photocopies of muster rolls for Harman (1861-1863) and correspondence (1881-1888) by his mother and relatives trying to secure his pension for his mother.

The collection contains diaries, correspondence, manuscripts, course notes, photographs, autobiographical information, both personal and professional, of Rollin H. Baker, Museum Director and Professor in the Department of Zoology and the Department of Fisheries and Wildlife at Michigan State University.