He attended the public schools, and was graduated from the law department of Transylvania University in Lexington, Kentucky, in 1846.
Simms served as a captain in the United States Army throughout the Mexican War, and was elected to the Kentucky House of Representatives from 1849 to 1851.
He was appointed lieutenant colonel in the Provisional Army of the Confederate States on December 24, 1861, and was assigned to the First Battalion, Kentucky Cavalry.
He resigned his commission on February 17, 1862, having been chosen as one of two senators from Kentucky to the Confederate States Congress.
After the war, he engaged in agricultural pursuits, and died on his estate, "Mount Airy," near Paris, Kentucky, on June 25, 1898.