Bull and bear baiting were popular in England up until 1835 when they were outlawed. A Bill for the suppression of the practice was introduced in 1802, but was defeated due to it's popularity.
After 1835, dog fighting became more popular in England leading to the development of the English Bull terrier and the Staffordshire Bull terrier, which at one time were the same breed, but over time developed into separate breeds.
Charlie Lloyd's champion Pilot was one of these Staffordshire Bull terriers that was brought over from England to become the American Pitbull terrier. Many other immigrants from Ireland and England brought their Stafforshire Bull terriers as well.
Bull and Bear Baiting arenas shown on the "woodcut" map of London of c.1561 (the dogs are shown coming out of pens to each side),
Note the old English spelling of bull and bear baiting in this carving - "bolle bayting" and "beare bayting".
https://en.wikipedia.org/wiki/Bull-baiting