He's identified in the first, too: "
Taylor, the drummer boy with the
78th Regt. U.S.C.I. (U.S. Colored Infantry)"
And in the second: "Portrait of 'Drummer'
Jackson, a former slave serving as a drummer in the
79th United States Colored Troops"
It's not so much a lack of identification, as an abundance of it.
This is the before-and-after set of photos, but I don't know which identification is correct:
http://www.cdjewell.net/photos/MostViewed.cfm?Rank=15&Top=20