Spanish colonists were the first to introduce cattle to the New World. The steers of the Spaniards were not like the fat Herefords we see today. They were scrawny, tough beasts, which multiplied rapidly as Spanish settlements advanced north from Mexico City. In California and north of the Rio Grande in what is now southeastern Texas, cattle found an ideal spot where grass was always green, the climate mild, and the land well watered. Here cattle could graze, drifting and feeding, for hundreds of miles. Slowly, Spanish settlers learned how to care for cattle on the open range, to herd them on horseback, to identify their own animals by brands, to use the "round up" to mark newborn calves. It was on these open ranges that the vaquero, the original cowboy, was born.

By the time Americans filtered into Texas, the southeastern corner of the state was a great cattle range. The newcomers milk cows soon interbred with the local herds and produced a variety of strains, all tough and wiry, able to survive just about anywhere, on parched grass and during winter blizzards.