The Boston is among a small group of dogs who were "made in America". Originally it was bred from crosses between the bulldog and the terrier, and careful selection has produced a dog that is consistently marked and very true to type. He has distinctive white markings on a background of black, seal or brindle. Ears are upright and may be cropped or natural. Backskull is flat, muzzle is short with a well defined stop. His nose is of the braccocephalic type and he can be heard to snore at night. Most dogs with this type of nose are not highly athletic in nature since they do not have the breathing room required to be highly active, especially in the heat.