When Americans think about "the '60s," we don't usually mean the period from 1960 to 1970. Instead, we usually mean the years from late 1963 to around 1970.
I would date that era actually from one set of deaths to another set of deaths.
The first set was on one specific afternoon: Nov. 22, 1963.
On that afternoon, President John Kennedy was killed, and American politics changed almost overnight from optimism to the pessimism that still seems to have a stranglehold on us.
On that same afternoon, Aldous Huxley -- one of the lights of pessimistic humanism -- died in England.
Likewise, C. S. Lewis, one of the last of a certain variety of Christian humanist died.
And something changed after that afternoon. It's important not to assume that because something happened after another event, that the first caused the second. (In other words, I got out of bed this morning. My getting out of bed didn't make the sun rise. This is a fairly common logical mistake).
So I'm not saying that these deaths engendered that wild ride known as the 60s. But they are a useful marker.
The deaths that ended the 60s happened likewise on an afternoon, in Kent, Ohio, with the deaths of the Kent State 4: Allison Krause, Jeffrey Glen Miller, Sandra Lee Scheuer, and William Knox Schroeder.
When those 4 died, there was an explosion of protests around the country, but the wind seemed to go out of the sails of the protests after 6 weeks, and likewise something changed.
I was reminded of the coincidences of the deaths of Nov. 22, 1963, when posting earlier a review of C. S. Lewis' book, The Abolition of Man. While Abolition is not one of Lewis' best-selling books, it's one of the more important ones in my opinion, and represents an earlier, perhaps more well-thought Christian humanism.