If you live in the US you're familiar with imported horses - breeds rarely found here a few decades ago that are now popular or exotic breeds still rarely seen outside their homelands. From Friesians to Gypsy Vanners, Hanoverians and Holsteiners to Akhal Tekes, foreign breeds can be found around the US. For that matter the Arab and Thoroughbred were brought here centuries ago and have left their mark on many US breeds. (ETA: of course you could go further with this, as all the modern horses in the US originated at some point from imported horses!)
But what about the other way? Did you know that many US breeds can be found around the world? Take a look at a few international fans of some of our homegrown horse breeds:
Saddlebreds in South Africa - the first Saddlebreds were taken to South Africa in 1916 (read more about the history here). In fact some bloodlines that are now scarce in the US can still be found there, and US breeders have been known to bring back stock from South Africa's breeders.
Quarter Horses in Brazil - Brazilians love the American West, and Quarter Horses are popular for barrel racing, reining, cutting and other traditional cowboy sports.The linked page says there are over 300,000 registered Quarter Horses in Brazil!
Moreover there are:
Of course there are a few Rocky Mountain Horses in the UK, too, as I wrote about a while ago.
Know of others? Mention them in the comments!