Getting into this are you?
Just a note: Franklin A. Graham, U.S.N. was living at 171 Duffield St., Brooklyn NY, in 1867. I'm trying to determine if that area was an African-American neighborhood at that time. He could have been stationed at the Navy Yard in Brooklyn after the war.
NOTE: I found more info: his widow was Elizabeth L. Graham and he died 4 Sept 1873 (born 1830) buried in Springfield, Delaware County, PA