Altamont wasn’t the end of the 1960s. It wasn’t even the end of peace and love. There was rioting at the original woodstock. The fences were torn down. Terrorists (yippies and black panthers) blackmailed the promoters for $10,000 and still stormed the stage during the Who’s set to preach politics, they burned down the burger guy’s food booth...
The “1960s” era probably ends more resolutely with the ousting of Richard Nixon. After Nixon we are squarely into a new era. The 1970s end on Jan 20, 1981 as Reagan is sworn in, Jimmy is out, and the Iranian hostages are released.
To define a decade simply by year doesn’t work. Eras and generations (25 year birth to adulthood lifespans) are more appropriate.
I probably heard that before, but can't recall it. My father was living in NYC at the time and he and his friend (both about a decade older than the average attendee age at 30) were going to go up there on a lark, but they wisely decided against it. I think Altamont, while on the whole hardly much of a blip on the scale of things, tended to illustrate that whatever innocence (although dubious to claim to begin with) that went along with these "hippie concerts" was gone.
"The “1960s” era probably ends more resolutely with the ousting of Richard Nixon."
I think it was over long before then. You could make the argument that the '60s era of JFK ended at some point in the Spring or Summer of '68 (MLK/RFK assassinations and the resulting riots in major cities). Probably can call the "New Frontier" segment of the '60s (the optimistic, can-do spirit) and the "Hippie" segment from '68 to '71 with the breakdown of society in overdrive.
"After Nixon we are squarely into a new era. The 1970s end on Jan 20, 1981 as Reagan is sworn in, Jimmy is out, and the Iranian hostages are released."
Some disagreement on the post-Nixon era, but clearly the '70s ended with Reagan's election and the real end of the long national nightmare. I would fix the date of the end of the '80s as April 29, 1992. The Rodney King riots (which I missed being in by a single day) and also the end of the run of The Cosby Show that week, which exemplified perhaps the most positive portrayal of Blacks on television and what could positively be accomplished during the Reagan era (although by which time, already Hollywood was mocking the image with the backlash of trash sitcoms and music).