200 years? And went wrong in 1970? The USA absolutely wasn't a good system in 1770, and has sucked for a lot of people for large fraction of those years.

Who could vote was all over the place for a long time: https://en.wikipedia.org/wiki/Timeline_of_voting_rights_in_t...

Civil War was about as far from "balanced" as you can get, and the problems weren't even on the axis of "hammer and sickle" vs "single megacorporation".

The New Deal was a radical change in the economic organisation of the USA, basically ended Laissez-faire. Before that point, there was enough social unrest that, for the people at the time, I think it wouldn't have seemed at all implausible the USA would have faced an actual communist revolution similar to the one in Russia, because of events such as e.g. https://en.wikipedia.org/wiki/Battle_of_Blair_Mountain