Hi Michelle I believe that this is a problem caused by multiple Hiram Roberts. First we have Hiram H. Roberts of the 28th Maine Nine Month Regiment, who died on Aug. 20th 1863 in Bellefontaine,Ohio. He was returning to Maine from his service in Louisiana(See Washington County, Maine USGENWEB -Military). The second was Hiram M Roberts first of the 37th Iowa Infantry and latter an officer of Company I 65th Regiment United States Colored Troops. This is who is buried in Baton Rouge. The Third is Hiram Roberts of the 22nd Maine Nine Month Regiment, who also served in Louisiana. The first Hiram could not have fathered a child that was born in 1864, the second was from Iowa, so the third Hiram might be your ancestor. Use the NPS Soldiers and Sailors System to see brief records of these different men.