You can camp for free on national parks and most state parks as well. So I'm wondering what exactly OP is going on about unless being super edgy.
I interpreted OP's statement as referring to other, unsaid aspects of (US) American life that they saw in contrast while camping in Europe--not as referring to the "free" in "freecamping" as a significant difference between the two regions. I'd be interested in what those differences were, though.
In some regions you are permitted to camp _on someone else's private property_ given you adhere to specific, and somewhat strict, rules.