United States, The coming of the war

Faced with a fait accompli, Lincoln when inaugurated was prepared to conciliate the South in every way but one: he would not recognize that the Union could be divided. The test of his determination came early in his administration, when he learned that the Federal troops under Major Robert Anderson in Fort Sumter, South Carolina—then one of the few military installations in the South still in Federal hands—had to be promptly supplied or withdrawn. After agonized consultation with his cabinet, Lincoln determined that supplies must be sent even if doing so provoked the Confederates into firing the first shot. On April 12, 1861, just before Federal supply ships could reach the beleaguered Anderson, Confederate guns in Charleston opened fire upon Fort Sumter, and the war began.