The SPMDTU, founded in Antonito on November 26, 1900, by Celedonio Mondragón and six others, is the oldest Hispanic civil rights organization in the United States. It was created to fight discrimination in the fields and mining industry and to defend property rights. In 1914, after a lengthy trial, District Court Judge Charles Holbrook ruled in favor of Maestas and Hispano children, saying that children who were prepared should be allowed to attend the school nearest them. The case is considered one of the earliest court victories for educational equity in the U.S. and may be the first documented case involving Mexican Americans.