ACT UP, the AIDS Coalition To Unleash Power, formed in New York in 1987 and was active through the early 90s. See this timeline for the group’s actions.
Some great imagery in the background of the trailer for the recent documentary How To Survive a Plague:
A brief video interview with Alex Juhasz, in which she talks about what AIDS and ACT UP meant for the construction of the clost (Sedgwick’s focus, of course) and about ACT UP’s legacy
[pdf transcript of the interview]