It is currently the dominant party in the state, controlling the majority of Missouri's U.S. House seats, both U.S. Senate seats, both houses of the state legislature, and all statewide offices, including the governorship.

Francis Preston Blair Jr. was the only Republican member of congress from a border state at the beginning of the American Civil War.

[1] Blair and other Unionists in Missouri supported the removal of John C. Frémont's military command and the rescinding of his emancipation order.

Brown wanted to send a delegation to Frémont's Radical Democracy convention.

[4] The Radical wrote the state constitution in 1865, which emancipated slaves[5] while Blair returned to the Democratic Party.