I bought "None Dare Call it Treason" when it came out in paperback, late '64 as I recall.
I wasn't the only one in my high school to do so.
My dad, who's a liberal in the old-fashioned sense, bought "None Dare Call It Treason" at about the same time. Probably the most influential piece I've ever read.
Same here. I learned of None Dare Call It Treason by word of mouth when I was in h.s. I still have it.