California Proposition 6 or Proposition 6, more commonly known as The Briggs Initiative, was an initiative on the California State ballot in 1978. Sponsored by John Briggs, a conservative state legislator from Orange County, the failed initiative would have banned gays and lesbians from working in California's public schools and came on the heels of a highly explosive rightwing campaign in Dade County, Florida to repeal one of the first gay rights ordinances in the U.S. With Anita Bryant as their spokesperson, the right temporarily succeeded in rolling back civil rights for gay men and lesbians.

The Briggs Initiative followed similar legislation that had passed in Oklahoma and Arkansas, banning gays and lesbians from teaching in public schools. It stated that any teacher that was found to be “advocating, imposing, encouraging or promoting” homosexual activity could be fired. It was the first attempt to restrict gay and lesbian rights through a ballot measure.

Hurting from these losses, the gay and lesbian community got organized. A huge coalition of predominantly progressive grassroots activists, led by out gay San Francisco Supervisor Harvey Milk under the slogan "come out! come out! wherever you are!", mobilized to defeat the Initiative. Throughout the state, gay men and lesbians went door to door in their cities and towns to talk about the harm the initiative would cause. They came out to their families and their neighbors and their co-workers, spoke in their churches and community centers, sent letters to their local editors, and otherwise revealed to the general population that gay people really were "everywhere" and included people they already knew and cared about. For a time the ballot measure was ahead in public-opinion polls, with about 61% of voters supporting it while 31% opposed it—a week before the election. The movement against it succeeded little in shifting public opinion, even though major organizations and ecclesiastical groups opposed it. Then former-governor Ronald Reagan a week before the election announced his opposition, and the anticipated landslide for the initiative became a landslide against the initiative, loosing even in Orange Country, in the largest shift of public opinion ever recorded within such a short time frame.

Some gay Republicans also became organized against the initiative on a grassroots level. The most prominent of these, the Log Cabin Republicans, was founded in 1977 California, as a rallying point for Republicans opposed to the Briggs Initiative. The Log Cabin Club lobbied Republican officials to oppose the measure, and shortly before the election, after the polls had changed in the opponents' favor due to the mobilization of thousands of activists across the political spectrum, even former Governor Ronald Reagan, later President, was finally moved to publicly oppose the measure. The Initiative was defeated by more than one million votes.

Reagan opposed the ballot initiative sponsored by religious conservatives that would have barred homosexuals from teaching in the public schools. The timing is significant because he was then preparing to run for president, a race in which he would need the support of conservatives and moderates very uncomfortable with homosexual teachers. As Lou Cannon (Reagan biographer) puts it, Reagan was “well aware that there were those who wanted him to duck the issue” but nevertheless “chose to state his convictions.”

Despite a legend that circulated widely, a student worker named Grant Grays at the Tretter Collection in GLBT Studies at the University of Minnesota Libraries discovered that there was no editorial penned by Reagan but rather he sent a letter to a pro-Briggs Initiative group in which he opposed the initiative. The entire text of Reagan's letter of opposition was never printed in the public media. The most extensive excerpts from his statement were reprinted in the San Francisco Chronicle of September 24, 1978 where it was revealed that the future President opposed the Briggs Initiative. Reagan's actual letter allegedly stated, in part, “Whatever else it is, homosexuality is not a contagious disease like the measles. Prevailing scientific opinion is that an individual's sexuality is determined at a very early age and that a child's teachers do not really influence this.”

The initiative went down to resounding defeat, and even lost in Briggs’ own Orange County, at that time a stronghold of conservatism in the state. Its sponsors blamed Reagan for the defeat.[citation needed]