It's not just the US either. My house in London was built in 1970 and has a garage that will not fit a modern hatchback/compact in it. It might just about fit, but you wouldn't be able to open the doors.
Guarantee you can’t find an American car built in 1970 that would fit either. Case in point, the 1970 Pontiac Bonneville Coup. A diminutive 2 door car that was a 18’ long by 6.5’ wide.