Scott is the only black Republican in Congress. The decision announced Monday makes him the South's first black Republican senator since Reconstruction and only the fourth black Republican ever in the U.S. Senate.
He takes over for Jim DeMint, who announced earlier this month he would forgo the remaining four years of this term to take the helm of The Heritage Foundation, a conservative think tank. His resignation takes effect Jan. 1.
Scott started with a moment of silence for the school shooting victims in Connecticut. He says the country needs backbone to make difficult decisions.
Scott will server for two years. A special election for the term's remaining two years will be held in 2014.