The fifties were pretty bad... however, it was an imposition of Order which tipped the Chao back to the mess of disorder in the 60's. And the 60's are still affecting the US today... hell the Dem vs GOP fight that's happening right now is still the hippies vs The Man (even though the hippies are now the Man, so that's confusing as hell for them I think).
However, I will disagree with Roger on the 1800's... I mean I wasn't there like he was, but it doesn't seem to me that it was all that great for the 'people' either. Hell, we had corporations running roughshod over employees (ages 3 and up), having shoot outs with unions, controlling steel and oil with Iron Monopolistic fists and making sure 'the right' people got elected.
Before the Civil War, we had slaves and fighting between the 'liberals' and 'conservatives' over slavery. With Lincoln, we had the Federal Government manipulating the Public with the emotional "Free The Slaves" rhetoric, while actually fighting over stuff like taxes and the 'preservation of the Union'. After the civil war, we get lynch mobs, segregation, carpetbaggers, abuse of the South by the North, and overall a nation held together at gunpoint.
America died in 1777 I think...