I was escorted by two US Air Marshals from my gate to my plane in Miami when I tried to board a flight to the Bahamas and was carrying a spear gun in my hand. They took the spear gun and stowed it on the airplane, and FAs handed it to me when we landed in Nassau.
You saw African Americans board a flight in the 70s? I have no memory of seeing anything like that. The only folks without white skins that I saw were Puerto Ricans (non-blancos, as they say) heading home to San Juan from NYC.