ブルテリア
Eventually, out of crossbreeding Bulldogs and terriers, the English created the Staffordshire Bull Terrier. When the Staffordshire Bull Terrier came to America in 1817, Americans began to selectively breed for gameness and created the American Pit Bull Terrier (originally known as the Pit Bull Terrier), which is a unique breed due to its absence of threat displays when fighting and its docility towards humans. Bull Terriers, Staffordshire Bull Terriers, American Pit Bull Terriers and American Staffordshire Terriers are all breeds that are commonly labeled as "pit bulls". The fact that "pit bulls" were historically bred to fight bulls and bears has been used as justifications in some U.S. cities to implement Breed Specific Legislation.