Although secession from the Union had not been an issue in the campaign, talk of it began in the Southern states.[80][81]
Johnson took to the Senate floor after the election, giving a speech well received in the North, "I will not give up this government ... No; I intend to stand by it ... and I invite every man who is a patriot to ... rally around the altar of our common country ... and swear by our God, and all that is sacred and holy, that the Constitution shall be saved, and the Union preserved."[82][83] As Southern senators announced they would resign if their states seceded, he reminded Mississippi Senator Jefferson Davis that if Southerners would only hold to their seats, the Democrats would control the Senate, and could defend the South's interests against any infringement by Lincoln.[84] Gordon-Reed points out that while Johnson's belief in an indissoluble Union was sincere, he had alienated Southern leaders, including Davis, who would soon be the president of the Confederate States of America, formed by the seceding states. If the Tennessean had backed the Confederacy, he would have had small influence in its government.