Staffords share the same ancestry with the modern Bull Terrier, although the two breeds developed along independent lines, and do not resemble each other.

Modern Staffords more closely resemble the old type of bull terrier, and were first recognised as a purebred dog breed by The Kennel Club of Great Britain in 1935.

Dog breeders migrated away from the heavier bulldogs, and introduced terrier blood into their crosses for gameness and agility.

It was shortly before the American Civil War that immigrants from Great Britain brought their bull and terrier crossbreeds into the U.S.

The unregulated breeding history and inconsistent genetic makeup of the Stafford's early ancestry have led to misconceptions about its origins.

[3]: 18  Hinks used various undocumented outcrosses, including Dalmatians and Collies, that devotees of the original strain considered undesirable.

The KC recognises only four of the breeds and does not accept the AmStaff or American Pit Bull Terrier (APBT).

It is generally accepted that the Stafford descended from the 19th-century bulldog–terrier crosses that were later bred for dog fighting after blood sports were declared illegal.

[3]: 8–11 In the spring 2013 issue of The Stafford Knot, Jason Nicolai describes some important evolutionary factors in the breed standards of the Staffordshire Bull Terrier that are "very often misquoted and misunderstood.

[20] Some book authors have compared nineteenth-century drawings or paintings to the visual appearances of modern Staffords.

Author and Stafford enthusiast, James Beaufoy, wrote in his book Staffordshire Bull Terriers: a practical guide for owners and breeders (2016) that there is "interesting evidence" in some of the early 19th-century paintings that depict conformation and coat colour similarities of the modern Stafford when compared to the Old English Bulldog.

[22] Cairns believed a "Stafford-like animal existed at the turn of the 19th Century" and admitted, with the "possibility for slight prejudice", that "the only modern dog of this type is the Staffordshire Bull Terrier".

"[23] The writings of both Cairns and Beaufoy align in that the "Staffordshire Bull Terrier is a relatively 'new breed'" in the context of when it was first recognised by the KC.

[27] The Cruelty to Animals Act 1835 made blood sports illegal, and effectively stopped bull- and bear-baiting in the UK.

[31] In June 1935, the Staffordshire Bull Terrier Club was formed during a meeting at the Old Cross Guns pub in Cradley Heath; a breed standard was approved the same day, and further shows were held that year.

[21] Other pivotal breeders involved in acquiring breed recognition were Joe Mallen and actor Tom Walls.

[34][35] The early Bull Terrier breed developed by James Hinks as a conformation show dog was recognised by the AKC in 1885.

[35][34] In an effort to achieve AKC recognition of the English Stafford, Steve Stone organised the US Staffordshire Bull Terrier Club, 14 January 1967.

Dog imports continued, and the number of memberships and registered dogs increased but it would take nearly a decade of hosting sanctioned shows and demonstrating consistency in the breed standard by maintaining responsible breeding practices that the club would acquire official AKC recognition.

[39] A 2024 UK study found a life expectancy of 12 years for the breed compared to an average of 12.7 for purebreeds and 12 for crossbreeds.

[42] Neurological disorders identified in the breed include cerebellar abiotrophy, Chiari-like malformation, myotonia congenita and L-2-hydroxyglutaric aciduria.

[7][45] Relative to the breed's ancestral progenitors, the AKC states: "From his brawling past, the muscular but agile Staffordshire Bull Terrier retains the traits of courage and tenacity.

Happily, good breeding transformed this former gladiator into a mild, playful companion with a special feel for kids.

As a result, Staffords are considered among the breeds with a stigma attached relative to the "chav culture",[26] and have been termed "status dogs".

[57] They found heritable patterns in terriers "consistent with working roles involving catching and killing prey".

The proposal was rejected by Parliament;[60] therefore, Staffords are not banned under the UK's Dangerous Dogs Act 1991.

[62] The CDC and ASPCA are among several agencies and organisations that have stood in opposition to the "theory underlying breed-specific laws—that some breeds bite more often and cause more damage than others, ergo laws targeting these breeds will decrease bite incidence and severity" as they do not believe it has been successful in practice.