The Consenting Adult Sex Bill (Assembly Bill 489) is a consenting adult law, passed in California in 1975 and effective in January 1976, that repealed the sodomy law in California and made gay sex legal for the first time.George Moscone, an early proponent of gay rights, in conjunction with his friend and ally in the Assembly, Willie Brown, managed to get the bill passed, 21-20, repealing the existing Californian laws against sodomy. The repeal was signed into law by California Governor Jerry Brown. The Assembly had a much easier time passing the bill, with final vote on AB 489 being 45-26. Gov. Brown signed the bill on May 12, 1975. 
Assemblyman Brown had initially introduced the bill in 1970, resulting in an ugly five year fight in the legislature.