 It is a small to large breed which has been divided into four categories by some registering organizations, "Pocket", "Standard", "Classic" and "XL".Other organizations, including the UKC, have 1 consistent size standard.Founded in the United States between 1980 and 1990, the American Bully was produced using a foundation of American Staffordshire Terriers and American Pit Bull Terriers bred to several bulldog-type breeds.