After the election of Abraham Lincoln as president in November, 1860, the Southern slaveholding states seceded from the Union one by one. The Confederate States of America (CSA) was established, with its capital in Montgomery, Alabama. It was questionable if the people of the North would support an all-out war to preserve the Union and destroy the Confederacy. Despite the South's defiant actions, a large faction of Northerners were against the abolition of slavery and thought the seceding states were within their rights. The test, President Lincoln and his military commanders believed, would come with the first attack on a Union installation by Confederate forces.

By March, 1861, all federal military outposts except Fort Pickens in Pensacola, Florida, and Fort Sumter in Charleston, South Carolina, had been seized without resistance by Confederate forces. Confederate leaders claimed that these forts, located in territory...