Most modern Pit Bulls are believed to be descended from European bull dogs and different breeds of mastiffs that were once used in farm work. The mastiffs were known for their strength and power, so they were primarily used to help farmers with their bulls when it was time to bring them in from the fields.
The mastiff became known as the bulldog. The dogs main purpose was to protect the farmer from being gored by an enraged bull. The dog usually accomplished this task by biting onto the bull and hanging on until the bull relented. Since these dogs were used for protection from angry bulls, they had to have tremendous strength in their jaws and bodies. They also had to be stubborn enough to hang onto a stampeding bull, no matter what the bull did to them, to protect the farmer they worked for.
As time passed, these dogs started being used in bull and bear baiting. During this time it is believed some bulldogs were also bred with terriers to help make them better suited for these sports. By mixing with the terrier breed, the dogs were smaller and a great deal more agile than the regular bulldog. They also had more muscular bodies, which helped to enhance their...