It would not be inaccurate to state that the genesis of all mixed martial arts in the United States, comes from one place primarily, and that is Brazil. The roots of it go all the way back to the 1920's, as Carlos Gracie was studying jiu-jitsu, in his native country, under one of the renowned masters of the art, Mitsuyo Maeda. The entire Gracie family fell in love with jiu-jitsu, but it was Carlos' brother Helio who created a variation of it, and by necessity, as he suffered from dizzy spells and had to gear it to his own physical limitations. He did so by emphasizing ground work, submissions and choke holds, and thus what became known as "Brazilian Jiu-Jitsu" was born.
Helio built a reputation, and a clientele, by promoting himself through challenge matches, many of which came against competitors who practiced a different form of martial arts. Just about anything was allowed, including punches and kicks, and for this reason the nature of the competition took on the name of "vale tudo," which is Portuguese for "anything goes."