Pair of CDVs of Civil War Navy and Military Institute

Pair of CDVs of Civil War US Navy and a Military Institute image signed Fred Balcom. The people in the photos have very similar facial features leading me to believe they are related for that reason we are keeping them together. The US Navy image has a C. K. Bills New York Backmark and the CDV of Fed has a Slee Brothers Backmark from Poughkeepsie, New York