Just happened to stumble upon your message. I grew up in Bel Air, Maryland approximately 3 or 4 miles from the Booths' homeplace. It is located in Harford County, Maryland. You might be able to find something on the gen board for this county. I'm thinking the Booths stayed here for years and had descendants in Harford Co.

The Booths' Mansion was open to tourists and available for theatrical shows until recently. It's beautiful. And John Wilkes Booth had carved his initials on a glass window at the front of the house when he was very young. Our local Community College and the Harf Co govt teamed up to buy it when it went on auction last year. But a private owner got it. The local newspaper here really dogged the new owners out. (They even went as far as to accuse the man of not having proper business licenses, etc.) It was a very messy political situation! What a shame!

But anyway, hope I could be of help.