The Boston Terrier breed was started by Robert Hooper from Boston, Massachusetts, in 1870 when he acquired a dog of Bull and Terrier lineage. At this time in history, both ancestral breeds were shared in various forms but lacked breed recognition due to the undeveloped dog Registration industry at the time.
One of the typical terriers that were regularly accepted as a breed at the time was one known as the White's Terrier, which is now extinct. This terrier is a common ancestor also in the foundation of the American Pit Bull Terrier breed.
The White's Terrier was often bred with larger bulldog types to bring their size down for the initial purpose of ratting. Ratting was a gambling sport that often took place in holes or Pits dug in the center of pubs where a defined number of rats were released, and then a dog unleashed in the Pit for a specific timeframe. At the end of the allotted time, the number of rats that were killed was added up, and the dog with the most kills was the winner. This sport was perpetuated due in part to Bull baiting being made illegal.
Because space was limited in most pubs, the Bully breeds needed to be bred down in size for this new sporting and gambling activity; adding terrier to the mix was a natural conclusion as terriers were known for their natural inclination for small game hunting. This original activity is where the Pit Bull Terrier got its name. Many uneducated people on the Pit Bull make the mistake that the breed got its name first from fighting other dogs.
The Boston Terrier was developed in much the same way as the American Pit Bull Terrier. Instead of White Terrier and large Bully breeds being used for breeding, the White Terrier and smaller bully breeds such as the English Bulldog and French Bulldog were used to helping develop this newly forming breed.
Where the Pit Bull was bred for a working purpose, the Boston Terrier was bred for show purposes and was first shown in 1870. Originally known as the Olde Boston Bulldogge and the American Bull Terrier in 1893, it was officially changed to the Boston Terrier at the suggestion of James Watson.