The obvious difference is in size. Ears are uncropped. All colors are acceptable, with the exception of black and tan and liver which are to be disqualified in the showring. Ears are cropped or uncropped. The ears are cropped or uncropped.
Color is of no importance.
The ancestry of the Amstaff and the APBT have one breed in common, the Staffordshire Bull Terrier. The original Pit Bull Terrier was imported by the English, and later by the Irish immigrants, who brought their dogs and their tradition of blood sports with them to America. Old records indicate that dog fighting was alive and well, as early as 1775. From the time the Pit Bull Terrier was introduced to America, it was crossed with various fighting terriers. Their breeders, following the tradition of secrecy, kept no written records, such as pedigrees, and refused to sell to the general public.