Much of it began with the forty-eighters, a group of German immigrants.
Have to laugh at the discussion page at Wiki, cuz it looks as though someone had written that they were communists (many of them were Socialists).
Kindergarten, the "PHD" & state level intrusions into public education based on "the Prussian model" were among the things which were embraced by the US, brought here by this relatively small band of German revolutionary intellectuals.
http://en.wikipedia.org/wiki/Talk:Forty-Eighters
Speaking of Socialists, Victor L. Berger was elected to Congress in 1910.
http://en.wikipedia.org/wiki/Victor_Berger
Frank P. Zeidler recently died. He was the Mayor in Milwaukee until 1960.
http://en.wikipedia.org/wiki/Frank_P._Zeidler