The Civil War was far from over 150 ago in April of 1863. The North certainly had the momentum. New Orleans had fallen. The Union had won major victories at Shiloh and Antietam. With the Emancipation Proclamation, President Lincoln had transformed the war from a war simply to preserve the Union to a war to save the Union and end slavery.

In Allan Nevins' memorable phrase, “War became revolution.”

In the eyes of white Charlestonians, the president was a hypocrite. A Democratic writer sneered:

“Honest old Abe, when the war first began, denied abolition was part of his plan; Honest old Abe has since made a decree. The war must go on till the slaves are all free. As both can't be honest, will someone tell how. If honest Abe then, he is honest Abe now?”

Victory seemed far from certain in the main theater of the war, Virginia, where Gen. George McClellan would not fight. Northern troops had done badly at Fredericksburg, where, Nevins wrote, in “a short winter's day the Union army suffered the cruelest defeat in its history.” There was an outcry in the North at the great losses, and renewed determination to strike a dramatic blow. The idea of a grand naval siege of Charleston, described by the Northern press as the “nursery of disunion” and “the cradle of rebellion,” was born from these military setbacks.

The political climate in Washington and especially the desire of the Navy Department to win a great victory with its new ironclad warships (without the help of the army) added a sense of urgency.

Gustavus Fox, assistant secretary of the navy, still smarting from his ignominious failure at Fort Sumter in April 1861, pressed the attack. He was obsessed with capturing this “hotbed of secession.” He had, he said, two responsibilities: “First to beat our Southern friends; second, to beat the Army.” Fox had even testified before a congressional committee that the monitors were invincible and that a fleet of monitors could compel the surrender of Charleston.

Charleston was not of any great strategic importance; Lincoln was not optimistic; but as the place where “rebellion first lighted the flame of civil war,” the city had great symbolic value at a time when the Union needed a symbolic victory.

Adm. Samuel DuPont's chief of staff wrote, “The desire was general to punish that city by all the rigors of war.”

Gideon Welles, the secretary of the navy, wrote, “A desperate stand will be made at Charleston, and their defenses are formidable. Delay has given them time and warning, and they have improved them. They know also that there is no city so culpable, or against which there is such intense animosity.”

The New York Tribune had written even earlier, “Doom hangs over wicked Charleston. If there is any city deserving of holocaustic infamy, it is Charleston.”

From the Confederate point of view, Charleston was the ultimate symbol of the right of the Southern people to be free. It was the very place where Southern nationhood had first begun — politically and militarily. It had to be defended at all costs.

The assault on Vicksburg and the siege of Charleston were part of the overall Union strategy. The siege of Vicksburg commenced in early February, 1863; the fleet which besieged Charleston began concentrating in Port Royal in February and March of the same year.

“The ironclads,” the Civil War historian Shelby Foote has written, “might indeed be invincible; some said so, some said not; but one thing was fairly certain. The argument was likely to be settled on the day their owners tested them in Charleston harbor.”

Robert N. Rosen, an attorney, is the author of “A Short History of Charleston” and “Confederate Charleston.”