I remember my first plane trip, PHL-IND in June 1972. My parents made me wear a jacket and tie as "Flying is something you do dressed up." Today you have to get UNdressed to fly!
I was 14, I'm quite sure no one called me an "unaccompanied minor" but there was in fact someone to meet me at the other end. This was also before you even had to go through a metal detector to get on board.
Oh, I flew on something called TWA.