50 years ago was 1974. Wasn’t USA just coming out of the Vietnam fiasco at the time? Were economic things really that good? I think there was an oil crisis and people at least in Yugoslavia (where my parents were kids at the time) could only fuel up at gas stations on alternative days based on license plate.
Oh and if I’m not mistaken that was when Japanese cars started flooding the US market and US car manufacturing began its downward spiral into oblivion. The beginning of the end for places like Detroit.