The history of the pit bull-type dog reflects the history of its constituent breeds: the American Pit Bull Terrier, the American Staffordshire Terrier, and the Staffordshire Bull Terrier. There are an estimated 74.8 million owned dogs in the United States; however, the number of pit bull-type dogs has not been reliably determined. Animal shelters in the United States euthanized approximately 1.7 million dogs in 2008; approximately 980,000, or 58 percent of these were pit bull-type dogs.

American Pit Bull Terrier

The American Pit Bull Terrier is the product of interbreeding between terriers and a now-extinct breed of bulldogs to produce a dog that combined the gameness of the terrier with the strength and athleticism of the bulldog. These dogs were initially bred in England, Ireland, and Scotland, and arrived in the United States with immigrants from these countries. In the United States, these dogs were used as catch dogs for semi-wild cattle and hogs, to hunt, to drive livestock, and as family companions; however, some were selectively bred for their fighting prowess, and starting in the early 20th century, they began to replace the bull terrier as the "dog of choice" for dog fighting in the United States.

American Staffordshire Terrior

The history of the American Staffordshire Terrier is rooted in its bulldog and terrier ancestry, for it was the interbreeding of the bulldog's courage and tenacity with the spirit and agility of a terrier that produced the "Bull-and-Terrier Dog", "Half and Half", and at times "Pit Dog" or "Pit Bullterrier" that later assumed the name in England of the Staffordshire Bull Terrier.

Staffordshire Bull Terrier

The Staffordshire Bull Terrier had its beginnings in England many centuries ago when the bulldog and Mastiff were used for the sports of bull-baiting and bear-baiting; in the Elizabethan era, breeders produced large dogs for these sports but later on the 100-120 pound animal gave way to a small, more agile breed of up to 90 pounds.

Bull Type

Characterized by heavier bone and more mass. This type falls more toward the bulldog ancestry. Some what shorter on one leg and heavier moving, they also have more tendancy toward looser, thicker skin. Although pictured as a bitch, both dogs and bitches can be of this type. The same rules of general soundness apply - This type should not be preferredf over the others as it can be quickly exaggerated, losing the athleticism and grace of the terrier influence.

Moderate Type

The perfect blending of the gbull and terrier background - with the strength and musculature of the bulldog, and the grace and agility of the terrier. If any type should be preferred, this would be the one.

Terrier Type

Showing a strong relationship to the terrier in the background, this body type is quick, agile, tight, sometimes leggier, lighter boned, carrying less muscle mass. This type is ofter stylish and elegant. This type should not be preferred over others, as it can be quickly exaggerated, losing the muscle mass that is desirable in the breed.