You can’t be gay today without reference to this time. Although I was a small child when the march took place, the images of it feel like documents of my own ancestry. I came out gradually and anxiously: moved in with my first boyfriend when I was 23 in 1987, and thereby grew honest with friends and family; wrote a novel with gay themes that was published when I was 31; joined the board of the National L.G.B.T.Q. Task Force only in my early 40s, around the time I married and had children and realized that gay pride had become a personal imperative. I’ve been an activist since, but I didn’t ascend into radicalism as a student, and I can only think that if I had been 20 when that first march took place, I’d have been peering at it anxiously from a distance, a pusillanimous stance I now regret. Pride is an internal and an external state, a sense of self and an outlook on the world. It comes with both privileges and obligations.

A few years ago, I was contacted by a reporter from my high school paper who was writing an article with the working title “Gay at Horace Mann: A Historical Perspective.” That made me feel as if I were 108 years old. But the nature of generational change was evident when the student journalist asked me why I hadn’t come out in high school, and seemed unable to parse my response. I patiently explained that in the 1970s, no one came out in my high school, that, indeed, most people didn’t come out even when they were no longer in high school, that I would have feared the response from my parents and my peers, that I would have been a social outcast and a laughingstock. I said that when I played Algernon in “The Importance of Being Earnest” my senior year, it was pretty obvious to everyone that my most terrifying secret was essentially common knowledge, but the idea of talking about it in high school no more crossed my mind than did the possibility of dropping out and becoming a professional surf instructor on Oahu.

So I come to these photographs abashed. I admire the people, braver than I, who were out for the first march. I feel such gratitude that these men and women had the wherewithal to declare themselves when doing so was still so acutely dangerous. I have benefited from their willingness to fight scorn with scorn. There is a righteousness even in the photos of people who seem to be there for a good time. The presumption that gay people were emasculated, weak, impotent had been defied by the Stonewall uprising, but this was something new: not people cornered by the police who fought back, but an open and immediate assertion by people who unprovoked declared their identity.