... and swear by our God, and all that is sacred and holy, that the Constitution shall be saved, and the Union preserved." 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. 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. Johnson returned home when his state took up the issue of secession. His successor as governor, Isham G. Harris, and the legislature organized a referendum on whether to have a constitutional convention to authorize secession; when that failed, they put the question of leaving the Union to a popular vote. Despite threats on Johnson's life, and actual assaults, he campaigned against both questions, sometimes speaking with a gun on the lectern before him. Although Johnson's eastern region of Tennessee was largely against secession, the second referendum passed, and in June 1861, Tennessee joined the Confederacy. Believing he would be killed if he stayed, Johnson fled through the Cumberland Gap, where his party was in fact shot at. He left his wife and family in Greeneville. As the only member from a seceded state to remain in the Senate and the most prominent Southern Unionist, Johnson had Lincoln's ear in the early months of the war. With most of Tennessee in Confederate hands, Johnson spent congressional recesses in Kentucky and Ohio, trying in vain to convince any Union commander who would listen to conduct an operation into East Tennessee. Military Governor of Tennessee Johnson's first tenure in the Senate came to a conclusion in March 1862 when Lincoln appointed him military governor of Tennessee. Much of the central and western portions of that seceded state had been recovered. Although some argued that civil government should simply resume once the Confederates were defeated in an area, Lincoln chose to use his power as commander in chief to appoint military governors over Union-controlled Southern regions. The Senate quickly confirmed Johnson's nomination along with the rank of brigadier general. In response, the Confederates confiscated his