According to Don Cousins' book 'The Magnificent Gorilla', John Daniel II was kept as pet in London from 1923 to 1927. During this time he was taken on tours of Europe and America. His owners had previously kept the original John Daniel.
That's right. It's a really sad story because he was brought up as if he was a human until he got too big and ended up being bought by Barnum's Circus and kept in a cage in New York. The rumour was that he died of a broken heart because he missed the lady who had kept him in England (and was probably desperately unhappy at his change in circumstances). Apparently, she set sail for New York when she heard he was sick, but didn't arrive in time.