I am also tracing Bainbridges. My ancestor was Sara Bainbridge, 1809-1897. She was born near George's Hill (now a part of Fairmount Park), in Philadelphia, PA. She married William Kephart in 1828 and had 5 sons: John, Charles, William, Sylvanus, and Alfred. All 5 sons served in the Union Army during the Civil War. I have a photograph of Sara that was supposed to be made into a portrait that was to hang in the GAR post in Germantown in Philadelphia. I also have her obituary, which mentions that she was a relative of a famous Revolutionary War hero.
Any information that you could share would be greatly appreciated and I would be happy to share as well.