As governor, Tillman had the legislature call a convention to draft a new constitution in 1895 for the purpose of disenfranchising the last black voters in the state. Tillman always considered this his greatest achievement.
Tillman went to the U.S. Senate in 1895, where he remained until his death in 1918. He used the Senate floor and the Chatauqua circuit to become the nation's loudest and most famous proponent of white supremacy, or in his own words, "preaching to those people the gospel of white supremacy according to Tillman."