I can remember people carrying rifles & shotguns in the rear window of their pickups - in and around Los Angeles. You could even take your M1 Carbine to school for ROTC. Things changed after the Watts riots in 1965.
My NW Chicago Suburbs HS had an NRA-sanctioned rifle team, from 1963-1967, and I used to carry my scoped Mossberg 144LS .22cal in a rifle case to school 3x/week, lock it in my hall locker w/ ammo, and we’d compete after school. No big deal. That all ended after the 1968 MLK-RFK assassinations, I heard while away in college.