As a bit of trivia on the subject of Booth, Wikipedia says that Cherie Blair is a four times removed cousin of JWB. I wonder if that's true or just the overactive imagination of someone who knows that her maiden name was Booth.
Booth's mother's name was Mary Ann Holmes. She was born in England and ran away with a then-very married Junius Brutus Booth. My great-grandfather's surname was Holmes. He was born in Canada and is buried there. I've often wondered if there was any connection between the Holmes on my mother's side of the family and Booth's mother's family. So far I haven't found anything, but that doesn't mean they weren't related.
There is a family line that claims they are descended from an illegitimate child fathered by J.W. Booth. At the moment though, I can't remember the name of the woman he was supposed to have impregnated. I met one of them years ago at an assassination symposium in Maryland.