There is also a smooth-coated variety; some breed organisations, including both the American and the Canadian Kennel Clubs, consider the smooth-coat and rough-coat dogs to be variations of the same breed.
The Welsh variety was small and nimble, domesticated and friendly, and also herded goats.
When the English saw these dogs at the Birmingham market, they interbred them with their own variety of sheepdogs, producing a mixture of short- and long-haired varieties.
It is from England that we find the famous pillars of the breed, from which the American fanciers sought not only their next big winner, but also their foundation stock.
By the turn of the century, the American Rough Collie was in a state of continued development. American show prizes were dominated by the British imports.
After the industrial revolution, dog ownership became fashionable, and these early collies were believed to have been crossed with the Borzoi (Russian Wolfhound) to get a more "noble" head (longer muzzle), which is today one of the true characteristics of the Rough Collie.
It is not known conclusively if the Borzoi cross made it into the mainstream of the breed.
The dogs were bred with great care in order to assist their masters in the herding and guarding of their flock.
Without a doubt, it is to the English fancy of the late 1800s that the breed owes its development as a popular show dog.
Collies in the US are sometimes reported to be over a hundred pounds – a large collie typically weighs no more than 70 pounds. The UK standard calls for dogs to be significantly smaller than those under the American Kennel Club.