The American Shorthair (ASH) is a breed of domestic cat believed to be descended from European cats brought to North America by early settlers to protect valuable cargo from mice and rats, there are not a great variety of mixed breeds with American Short Hair heritage. According to the Cat Fancier's Association, in 2012, it was the 7th most popular breed of cat in the United States.
When settlers sailed from Europe to North America, they carried cats on board – ships' cats – to protect the stores from mice. For instance the cats that came over on the Mayflower with the Pilgrims to hunt rats on the ship and in the colony. Many of these cats landed in the New World, interbred, and developed special characteristics to help them cope with their new life and climate. Early in the 20th century, a selective breeding program was established to develop the best qualities of these cats.The American Shorthair is a pedigreed cat breed, with a strict conformation standard, as set by cat fanciers of the breed and the North American Cat fancy associations such as The International Cat Association (TICA) The breed is accepted by all North American cat registries. Originally known as the Domestic Shorthair, the breed was renamed in 1966 to the "American Shorthair" to better represent its "all-American" origins and to differentiate it from other shorthaired breeds. The name "American Shorthair" also reinforces the fact that the breed is a pedigreed breed distinct from the random-bred non-pedigreed domestic short-haired cats in North America, which may nevertheless resemble the ASH. Both the American Shorthair breed and the random-bred cats from which the breed is derived are sometimes called "working cats" because they were used for controlling rodent populations, e.g. on ships and farms.