Michigan in the Civil War
O'Brien family.
The papers of this Berrien County, Mich., family include one diary (1864) and letters of William H. O'Brien, sergeant in Company A, 7th Michigan Cavalry and one diary (1863-1864, original and typescript) and letters of Patrick E. O'Brien, soldier in Company C, 25th Michigan Infantry. William H. O'Brien was a prisoner at Andersonville for a time, and one letter was written from there.