The first public endorsement of LGBT rights by an American labor union, however, did not occur until 1970, after the Stonewall Rebellion. In that year, the executive council of the American Federation of Teachers passed a resolution which denounced discrimination against teachers solely because the individual was a homosexual. A second step forward for LGBT labor activists came with the Coors beer boycott. As part of its anti-union efforts, the company administered lie-detector tests to prospective employees asking about their union views. Among the questions also asked was whether the job applicant was a homosexual. In 1974, the Teamsters were attempting to organize workers at Coors. Two straight Teamster organizers approached San Francisco gay community leaders Howard Wallace, a teamster union activist, and Harvey Milk, then an emerging political activist, about supporting the boycott. Wallace and Milk agreed, if the Teamsters would agree to promote the hiring of openly gay truck drivers. The Teamsters consented. The Coors boycott took off in San Francisco, and spread nationally. In California, the market share of Coors dropped from 40 percent to 14 percent. Facing this boycott, Coors stopped asking its applicants about their sexuality.