I don't know the circumstances of that particular soldier, apart from what's in his service record, but to my knowledge no blacks served in Arkansas U.S. volunteer (U.S.V.) regiments. The Union army was pretty strictly segregated. Blacks were enlisted in their own regiments (U.S. Colored Troops -- U.S.C.T.), normally serving under white officers.

There is some anecdotal information that some blacks or mulattos who could pass for white served in the Arkansas U.S.V.