Released a few months earlier, I didn’t hear this till early spring 1967. Driving to my maternal grandparents’ home in Milan, NY…a bit outside Red Hook in Duchess County. There was a family favorite coffee stop west of the Connecticut state line…and this was on the juke box.
Someone else had played it. I heard it and went to the juke box to see who this was, the name of the song. And played it another 3 or 4 times before we left and continued on to Milan.
Bought the 45 when I got back to Connecticut.
Couple guys we all eventually heard of, one from Texas, one from Canada, wrote a bunch of songs together, singing and playing in the band. Stephen Stills, Neil Young. Stills wrote and sang the lead on this one.
Eideard 
“Although “For What It’s Worth” is often considered an anti-war song, Stephen Stills was inspired to write the song because of the Sunset Strip curfew riots in November 1966—a series of early counterculture-era clashes that took place between police and young people on the Sunset Strip in Hollywood, California, beginning in mid-1966, the same year Buffalo Springfield had become the house band at the Whisky a Go Go on the Sunset Strip.” https://en.wikipedia.org/wiki/For_What_It%27s_Worth#Background
There’s a very nice cover by Los Lobos…with a tribute in the intro.