Maynard left his teaching position at East Tennessee College in the early 1840s to pursue a career in law, and quickly developed a reputation among his peers for his reasoning ability and biting sarcastic style. He spent much of his first two terms in Congress fighting to preserve the Union, and during the Civil War, he consistently urged President Abraham Lincoln to send Union forces to free East Tennessee from its Confederate occupiers. Maynard returned to Congress after the war, but being a Republican in a Democrat-controlled state, he struggled in statewide elections.