Mules are not native to America. We can hold the first president of The United States of America responsible for their presence in America.
George Washington developed an interest in the animal when he heard that farms throughout Spain were using a nifty work animal that was stronger and more sure-footed than either the horse or the donkey. Not only that, it ate less. He asked the U.S. ambassador to Spain to inquire about the critter. In what was probably the most important task of his assignment, the ambassador learned it was the infertile offspring of a jackass and a horse mare.
In 1785, King Charles III of Spain sent Washington a male as a gift. George liked him and named him appropriately "Royal Gift". He became impressed with the little guy and spent time in the 15 years before his death breeding mules. Mount Vernon became host to 58 working mules and regional farmers began breeding their own stock from George's. The mule was America's favorite plow animal until the advent of the tractor.
SHOWMANSHIP HANDLERS 1 7 YEARS AND YOUNGER