How many people own dogs in the United States?

Originally bred from bull-and-terrier crosses brought to America from England and Ireland in the 1800s, they were popular in emerging cities for the sport of dog fighting. As the country grew, many dogs traveled with settlers to new homesteads where they were sometimes used as working dogs on farms. When bred for fighting, the breeder would look for strength, gameness, and lack of aggression towards people. Any fighting dog that showed aggression towards its owner or handler would be culled immediately. This created a line of strong dogs that, while being dog aggressive, would not turn on their owners. In the late 1800s to early 1900s, two clubs were formed for the specific purpose of registering APBTs: the United Kennel Club and the American Dog Breeder's Association. After dog fighting was made illegal in the United States, many dog owners wanted to legitimize the breed and distance it from its fighting roots. The name "Staffordshire Terrier" was adopted by some owners and was recognized by the American Kennel Club in 1936. Later, the word "American" was added to reduce confusion with its smaller cousin, the Staffordshire Bull Terrier. Not all breeders, however, agreed with the standard adopted by the AKC, and continued to use the name APBT for their lines. Much confusion still remains in regards to the APBT, the AST, and the SBT.