The Australian shepherd is a breed

Dog breed

Dog breeds are groups of closely related and visibly similar domestic dogs, which are all of the subspecies Canis lupus familiaris, having characteristic traits that are selected and maintained by humans, bred from a known foundation stock....

 of herding dog

Herding dog

A herding dog, also known as a stock dog or working dog, is a type of pastoral dog that either has been trained in herding or belongs to breeds developed for herding...

 that was developed on ranches in the Western United States

Western United States

.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...

. Despite its name, the breed, commonly known as an Aussie, did not originate in Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 They acquired their name because some of the Australian sheepdogs arrived in the United States with boatloads of Australian sheep. The breed rose gradually in popularity with the boom of western riding after World War I.