And it has all occurred fairly recently, and quite quickly. I would be curious to know if any studies have been conducted to try to explain why this has happened. It wasn't all that long ago that homosexuality was actually a crime, and even where laws against it were not enforced, there was no social sanction against abusing and persecuting homosexuals; discrimination was rampant, and violence common.

It seems the change started with the Stonewall Riots in 1969, but it it hard to imagine that there were no precursors or foreshadowings for that event. The Riots did not arise in a vacuum, they were the result of long repressed pressure that finally exploded. A lot happened in the 1960s, with Civil Rights, Gay Liberation, Women's Lib, the Anti-War and Environmental movements all seeming to arise at once.

Even long hair, made popular by the Beatles and other rock bands, was a really big deal. No one who wasn't socially aware and in tune with pop culture in the 60s can possibly imagine how jarring, how bizarre long hair on men was then. You could get beat up on the street for just wearing your hair wrong in those days, even though there were plenty of fairly recent historical counter-examples such as General Custer, Wild Bill Hickock, Buffalo Bill Cody, not to mention the founders, who either had long hair or owned wigs to simulate it.

Granted, all of these social changes had histories, and they no doubt influenced each other, but it is still notable that it was in the USA.
in the last half of one decade, when it all seemed to happen at once, for no reason.

It was a time of great liberation and freedom for some, and for many others, a time of uncertainty and fear and terrible change. How do changes like this suddenly occur in a society? I was there, I saw it happening and was old enough to understand it, and I haven't a clue. I don't even know if a question like that CAN be answered. There must be a reason, but I doubt if anyone knows, or even if they did, how they could possibly go about proving it to anyone else. Sometimes natural phenomena are simultaneously undeniable and unexplainable.

Fashions change, look at pictures of the US presidents and note how hair on scalp and face has changed over the last 200 or so years. Moustaches, sideburns, beards come and go. But I'm not just talking about fashion, I'm talking about attitudes. Culture does seem to have a life all its own, totally independent of those human atoms that make it up.