I don't recall gay marriage being considered seriously until the Hawaii cases in the mid 1990s, but there were always examples of civil disobedience and applying for marriage licenses. Someone tried in Boulder, Colorado in the late 1970s and that may have made the news.
I don't think it was taken seriously as a policy objective until Andrew Sullivan presented an argument in its behalf approximately 20 years ago and the judiciary in Hawaii appeared open to ruling on it when a case was filed, as I said, in the mid 1990s. AIDS, and particularly funding for treatment and research, was an overwhelming concern from the early 80s through the mid 90s that would have rendered marriage an unfavorable target for activism, especially because it was so unlikely. Other competing issues were raising the ban on gays in the military, the ongoing fight against sodomy laws leading up to Bowers in 1986 and in the states in its aftermath, and non-discrimination laws, again in the states.
A caveat: I only came out in 1994, so I wouldn't have been fully aware of previous history.
I probably wasn't as clear in my post as I should have been, and I don't think we disagree much on the timeline. I meant that in the '80s was the beginning of the gay rights movement on the heels of the AIDS epidemic. Gay marriage came up as an issue after the gay rights movement was established. A starting point in the '90s is consistent with that.
