1844 Democratic National Convention and was elected to represent Kenton County in the Kentucky House of Representatives the following year. He was reelected in 1846 and 1848. In 1849, he was chosen as a delegate to the state constitutional convention that produced Kentucky's third state constitution. In 1850, he, Madison C. Johnson, and James Harlan were appointed as commissioners to revise Kentucky's civic and criminal code. Their work, Code of Practise in Civil and Criminal Cases was published in 1854. He was again one of Kentucky's delegates to the Democratic National Conventions in 1848, 1852, and 1856, serving as a presidential elector in 1852 and 1856. U.S. Representative In 1857, Stevenson was elected to the first of two consecutive terms in the U.S. House of Representatives. For the duration of his tenure in that body, he served on the Committee on Elections. He favored admitting Kansas to the Union under the Lecompton Constitution. Like many Kentuckians, Stevenson was sympathetic to the southern states' position in the lead-up to the Civil War, but he opposed secession as a means of dealing with sectional tensions. In the 1860 presidential election, he supported his close friend, John C. Breckinridge. Desiring to avert the Civil War, he advocated acceptance of the several proposed compromises, including the Crittenden Compromise, authored by fellow Kentuckian John J. Crittenden. He blamed the Radical Republicans' rigid adherence to their demands for the failure of all such proposed compromises, and on January 30, 1861, denounced them in a speech that the Dictionary of American Biography called the most notable of his career in the House. Stevenson was defeated for reelection in 1861. For the duration of the war, which lasted until April 1865, he stayed out of public life in order to avoid being arrested as many other Confederate sympathizers were. After the war, he was a delegate to the National Union Party's convention in Philadelphia, Pennsylvania, in 1865. He was a supporter of the Reconstruction policies of President Andrew Johnson. Governor of Kentucky Ex-Confederates dominated the Kentucky Democratic convention that met in Frankfort on February 22, 1867. John L. Helm, father of the late Confederate general Benjamin Hardin Helm, was nominated for governor and Stevenson was nominated for lieutenant governor. The entire Democratic slate of candidates was elected, including Stevenson, who received 88,222 votes to R. Tarvin Baker's 32,505 and H. Taylor's 11,473. The only non-Confederate sympathizer to win