During the US Civil War, E. Floyd Barnum served as Commissary Sergeant and later as 1st Lieutenant, Company "G" 111th USC Volunteer Infantry. This was a federal military unit, not affiliated with any individual state.
In the 1875 Minnesota Territorial Census for Glendorado, Benton County, the family of Erwin F. Barnum was enumerated as follows:
E. F. Barnum, 37, M, W, b. Ohio, Both parents b. Ohio
A. D. Barnum, 26, F, b. North Carolina, Both parents b. North Carolina
Ed. F. Barnum, 7, M, b. Ohio, Father b. Ohio, Mother b. North Carolina
Roger G. Barnum, 1, M, b. Minnesota, Father b. Ohio, Mother b. North Carolina