It is best to start with a short view based on the theory of 'your present is in your past'. The story begins with the Bulldogs, the cattle driving and baiting dogs of the medieval England. These huge, agile, massive built-up dogs are not to be confused with the dogs today known as 'English Bulldog'.

The entrepreneurs of the era sensitive to circus shows soon realized that the respected features of the butchers' dogs can be put to good use in different ways - and here we are at the shameful world of animal fights. At these extremely popular shows Bulldogs not only fought with bears and wolves successfully but they also took up arms with each other in bloody battles. In the late 1700's, the cross of Bulldog and Fox Terrier also came into sight at these battles.
The owners' expectations from the cross - breeds were stronger nimbleness, agility (meaning more success in fights), which expectations were justified. These dogs, even though they had smaller bodies than the Bulldogs, during a couple of years wiped out their direct progenitors from the arenas.
In the early 1800's the breeding of the Bulldog and Fox Terrier cross-breed took two directions in England: on one hand James Hink bred the English Bullterrier, on the other hand there were the Staffordshire Terriers - named after Staffordshire area which was famous for its mines and heavy industry.

These were also the years of a mass emigration from Europe to America: in the hope of a better life those boarding the ships took not only their personal belongings but their veteran Bulldogs and Bulldog - Terrier cross - breeds.  In the New World these dogs instituted the 'noble' fights and created many different types -varied from region to region, not rarely from part to part of a town - with a continuous crossing. These types with their very different colours and sizes became known on diverse names, however, all these names referred to their battle - origin or use, eg. Pit dog, Yankee Terrier, Yankee Bulldog. There was only one main breeding goal: more agility and better results in fights. But 'the better stays alive' brutal selection started a homogeneity since it soon turned out that one certain size - category embodies this, namely the 45 - 50 cm withers with a 25 - 30 kg weight. But beyond the more or less settled sizes there was still a countless number of types. The most striking differences were those of the body and the size of the head. However, it's worth remembering that the main goal in those days was not to strive for the most elegant outward appearance but for the perfect constitution and fighting spirit. By all means, the United Kennel Club, which was formed in 1898 in Detroit, Michigan, started to take records of these dogs under the name of American Pit Bull Terrier.

However, there were breeders and other dog - lovers who thought that these splendid animals were bled to death aimlessly at the fights and the amazing talents hidden inside them were wasted foolishly. They started to cross their dogs systematically, attaching great importance to the character and the every - day use over the perfect constitution. Their goal to create a dog which is capable of hard work, respects and loves the human being, has a balanced nervous system, and answers many purposes was fully reached. Thanks to them, the Amstaff formed the way it is now: an endlessly playful, kind and devoted partner who is ready to protect his loved ones and the values put in his charge.
As a result of the long lasting breeding procedure, the 'show - variety' deriving from the one-time gladiator separated more and more from those meant for fights. The new variety - we can't speak about a new type yet at the turn of the century - became popular and its committed adherents felt the need of clear distinction from the dogs named Pit Bull. After a few more or less apt names (where American Bullterrier is worth mentioning) the 'American Staffordshire Terrier' became generally accepted among the breeders. Also, The American Kennel Club started to register them under this name in the summer of 1936. This was also the time of finalizing the standards of the type which has been the same since then. However, another organization, the UKC (or the later formed American Dogbreeders Association - ADBA) accepts only the name Pit Bull Terrier to date and takes no notice of the Amstaff as an independent type. The FCI, the biggest international association registers only and exclusively the American Staffordshire Terrier. It doesn't mean that they protest against Pit Bulls, the one - time gladiators. It's only about that breeding for outward appearance has only became general recently among the owners of dogs having UKC, or ADBA registers, so as far as Pit Bulls concerned, we can't speak about a stock meeting the strict description of the type. In the sense of professional breeding, the Pit Bull Terrier can't be considered as an independent settled type because of the great diversity of its head and sizes.

source: 'www.kutya.hu'