June 18, 1977

1977 - An anti-discrimination Law is passed by Miami-Dade County. The ordinance that would make it illegal to discriminate on the basis of sexual orientation passes by a vote of 5-3. Anita Bryant leads the successful effort to repeal it later that year. 

Source: 

https://ronnisanlo.com/today-in-lgbt-history-june-18-3/