Santa Gertrudis cattle are a tropical beef breed of cattle developed in southern Texas on the King Ranch. They were named for the Spanish land grant where Captain Richard King originally established the King Ranch. This breed was officially recognized by the United States Department of Agriculture in 1940, becoming the first beef breed formed in the United States. The origin given by King Ranch is that it was formed by mating Brahman bulls with Beef Shorthorn cows, with the final composition being about three-eighths Brahman and five-eighths Shorthorn. In 1918, the King Ranch purchased 52 bulls of three-quarters to seven-eighths Bos indicus breeding to mate with 2500 pure-bred Shorthorn cows on the ranch. At this time, the American Brahman breed as such did not exist, nor were purebred Bos indicus cattle available in the United States.