Just Trivia

[L Verge]

"John Wilkes Booth's father was Junius Brutus Booth, born in London in
1796. He had a younger brother born in 1798, called Algernon Sydney
Booth. They were the sons of Richard Booth and Elizabeth Game, who
were married in London in 1795. It seems Algernon Sydney Booth was
the great-great-grandfather of the actor Tony (Anthony) Booth,
Cherie's father, who was born in Liverpool in 1931."

Steve Archer did a tremendous amount of research in writing his biography of Junius Brutus Booth: American Prometheus. Here is his citation on the short life of Algernon Sydney Booth, second son of Richard Booth and younger brother of Junius, Sr.:

Parish register for St. John's of Clerkenwell [London] recorded the burial of Algernon Sydney Booth, age five, on 2 June 1803. His birth in 1798 would thus agree with Junius Brutus Booth's later recollections of his brother; Algernon would have died when the future actor was seven.

James O. Hall had at least one paid researcher based in London to do his leg work when his own job responsibilities with the Labor Department prevented him from traveling. His genealogical work came up with the same story re: Algernon Sydney Booth.