SERVICE. of the 60th US Colored Troops--Post and garrison duty at Helena, Ark., till April, 1865. Expedition from Helena to Big Creek July 25, 1864. Action at Wallace's Ferry, Big Creek, July 26.

You might be able to contact the Delta Cultural Heritage Center in Helena, Arkansas. For the most part IF his body was NOT buried on the Battlefield at Wallace's Ferry, and even if it was, after the war all the known Union soldiers graves in the Helena area were exhumed and reburied in the Memphis National Cemetery. However, due to a heavy rain storm the names were washed off the coffin and lost to history resulting in a large number of unknown Union graves in the Memphis cemetery.

Good luck in you hunt.