In January 1861, after South Carolina had seceded following the election of Abraham Lincoln, Polk remained steadfast in his support for the Union. In a letter to a friend, he argued that Tennessee should not follow the path of South Carolina and submit itself to a "yoke shaped in an hour of madness and folly by political desperadoes." Following the attack on Fort Sumter in April 1861, however, Polk, like many Middle Tennessee Unionists, modified his position, stating that Tennessee must defend itself if federal troops invaded. He continued to waffle on the issue of secession in subsequent weeks.