Bulldog
The Bulldog, also known as British Bulldog or English Bulldog, was originally bred for the sport of bull baiting. England banned blood sports that involved animals in 1935, so the Bulldog was now without a job.
The Bulldog was then bred to be a companion dog. Aggressiveness was bred out of the dog, and they are now very sweet and loving dogs. They make excellent family pets.
According to the American Kennel Club, they are the 5th most popular breed in the United States.
The Bulldog is the mascot for the United States Marine Corps, and 39 American universities use the Bulldog as their mascot.