Johnson's term in the House expired March 3, 1819, but by August, he had been elected to the Kentucky House of Representatives, where he worked to secure passage of a law that abolished imprisonment for debtors in the state, though it did not pass until 1821. But when Senator John J. Crittenden resigned in November 1819, the legislature was called upon to fill the seat. The following month, the General Assembly elected Johnson to the Senate in a 68–53 vote over John Adair, who would be Kentucky's next governor.