George Wilkes is holding the banjo. He was a known for his female impersonations. He died October 1, 1870 in Memphis, TN (which means that the banjo he is holding was built in the 1860s).
Ed. Marble is standing left. He died August 6, 1900 in Brooklyn, NY.
A. C. Stone is standing on the right. He was a clog dancer. He died on November 11, 1866 (that now puts the banjo pre mid 60s at the latest).
The "Boot Black" routine must have been a laugh riot as it continued to be a standard well into 1900. I've read it... I guess I would have had to be there to get it.