He was the guy who started the Protestant Reformation by writing his infamous 95 Theses, and posting it on the Church in Wittenberg, thus becoming excommunicated by the current Pope.
The Roman contribution to the political theory which was adopted by the Founding Fathers was representative government. I hope that this is the answer that you were looking for.
1 & 2
There maybe more but those are the two I know of...
The Universal Negro Improvement Association and African Communities League
