I have a post in one of these threads with the history of them. There were several variants of them, back then they were called Bull and Terrier. They were bred for Hunting , Baiting and fighting. No they were not all successful in that purpose, example the English Bull Terrier " They were not known for attacking people, as bred for animals". Only 3 of the Bull and Terrier groups survived until the 1930s. But before that Dogs were brought over to America when its owners immigrated. They were actually bread again into the dogs we know today. They were used for companions, earth workers and even some herding/livestock protection.
They are not the dogs from Bull and Terrier group but share a lot of traits obviously. The American PitBull Terrier, American Staffordshire Terrier and English Bull Terrier. Prior to the 1970s, the public outrage was against Dobermans and German Shepards. There was a big rise in dog fighting, so the Media teamed up with a few groups of people to try and end it altogether. They actually spread some absurd stuff about the dogs, like Pits have Lock Jaws , Their bite force is 1600 Lbs, THey are more aggressive than all other dogs. Id suggests reading some research from more than one source and also both pro / anti pitbull.
All dogs are different and require different things. Some need more exercise vs some can barely move off the sofa. Some do just fine in small apartments while others need more space. Owners taking on dogs that are not experienced enough, do not have the time to properly train and not have enough time for the dogs needs. All Bully breeds are strong-willed and take a heavy but firm hand and a lot of attention. They will fight ya on everything they can ... stubborn little punks. Dog fighting is still a problem but not as much as the back yard breeders. Just pumping out dogs for profit not giving a dam about the Stud or ***** used. Thats where the Bully Mixes come in and become unpredictable ..... because who knows unless an expensive DNA test is given .