In 1814, Governor Shelby appointed Crittenden to fill the U.S. Senate seat vacated by his former teacher, George M. Bibb; later, however, Shelby learned that Crittenden was only twenty-seven years old, three years shy of the constitutional age requirement for senators.[18] Hence he returned to his seat in the Kentucky House, where was elected speaker over John Rowan.[19] He would retain the position from 1815 to 1817.[20]