Helm was first elected to the Kentucky House of Representatives in 1826; between 1826 and 1843 he served eleven one-year terms in the state house. In 1844 he was elected to the state senate, where he served continuously until he was chosen as the Whig Party nominee for lieutenant governor on a ticket with John J. Crittenden, famous for the Crittenden Compromise. The Whigs won the general election and Helm was elevated to governor on July 31, 1850, when Crittenden resigned to accept an appointment as United States Attorney General in President Millard Fillmore's cabinet.