I am interested in learning what getting into college was like in the US before the current era, when the change happened, and why it happened. Could you just get in to any school you applied to? Did it depend entirely on family and societal ties? Did it cost significantly less than it does now?

Edit: I would like to provide a more specific date, but one of the things I am interested in learning here is when this change took place. Presumably that would be around the 70s or 80s, but I'm not really sure.