Ross was an adviser to a group of Mexican Americans who were suing the city of Westminster for separating Mexican schools. The federal court decision in Mendez et al. v. Westminster is now a landmark civil rights victory against racial segregation in public schools. In 1947, Ross and Edward Roybal created the Community Service Organization (CSO) to organize Latino communities in Los Angeles. After registering thousands of voters in East Los Angeles, Ross moved to San José in 1953 to open a CSO chapter. There, he met a young apricot picker named Chávez, who joined the CSO. Ross also recruited Dolores Huerta and Gilbert Padilla for the organization, before they decided to leave CSO and establish the National Farmworkers Association in 1962.