Winfield Scott, 74, a lieutenant general, was commander of the U.S. Army in 1861. A vet­eran of the War of 1812 (during which he was a prisoner of war) and the Mexican-American War, he was a national hero. But that April, he was so infirm and, at 300 pounds, so overweight that he couldn’t ride a horse. After Fort Sumter fell, Scott wanted his accomplished subordinate, Robert E. Lee, to command the gathering U.S. forces. When the future Confederate general declined, Scott told him, “Lee, you have made the greatest mistake of your life.”

Abner Doubleday, 43, was a Union artillery captain and second in command at Fort Sumter. His guns were the first to reply to the Confederate bombardment. Historians say the later belief that he invented baseball is a myth. Doubleday, whose grandfather served at Bunker Hill, became a general, fought at Antietam and Gettysburg, and rode on the train when Lincoln traveled to deliver the Gettysburg address.

William Howard Russell, 41, the legendary war correspondent of the Times of London, had just passed through Washington. There, he met Abraham Lincoln, who struck him as a man willing to blend “justice with mercy.” Russell, who had covered the Crimean War in the 1850s, was in Norfolk, Va., headed for Charleston, S.C., when Fort Sumter was surrendered. It was a Sunday, he wrote, and people hurried from their churches, saying, “The Yankees are whipped.”

Mary Boykin Chesnut, 38, was the wife of South Carolina’s James Chesnut Jr., the first southern U.S. senator to resign as secession neared. Her famous diary, later hailed as a literary masterpiece, recorded in epic detail the life and death of the Confederacy. She watched the Fort Sumter attack from one of Charleston’s rooftops, where slaves had set up pre-dawn picnics for their masters and where, she recorded, there were prayers from the women and “imprecations” from the men.

Edmund Ruffin, 67, the white-haired, “fire-eating” Virginia secessionist, was in Charleston to be near the action and “commit a little treason.” He later claimed, erroneously, to have fired the first shot at Fort Sumter. Four years later, with the Confederacy in ruins, he draped himself in a Confederate flag and shot himself in the head, declaring his “unmitigated hatred . . . [of] the perfidious, malignant and vile Yankee race.”

P.G.T. Beauregard, 43, the Louisiana-born Confederate general in charge at Charleston, had been one of Sumter commander Robert Anderson’s best students when the Union officer was an artillery instructor at West Point. Beauregard had been superintendent at West Point for a few days in late January 1861; he was relieved for his secessionist views. Exotic and dashing, he was said to dye his hair to maintain his looks. On April 11, he demanded the fort’s evacuation. Anderson declined. The bombardment, and the Civil War, began the next day.

Abraham Lincoln, 52, whose election in November 1860 sparked South Carolina’s secession that December, was six weeks into his presidency. In his March 4 inaugural address, he told the South, “In your hands, my dissatisfied fellow countrymen . . . is the momentous issue of civil war.” He then ordered a relief expedition to Fort Sumter and informed South Carolina that it was coming. After the attack on the fort, his call for 75,000 troops to put down the rebellion brought the secession of four more states and four years of bloody conflict.

Louis T. Wigfall, 44, the hot-headed South Carolina native, ardent secessionist and former U.S. senator from Texas, was also in Charleston, where he swaggered around wearing a red sash and sword. An unofficial aide to Beauregard, he took a boat to Fort Sumter amid the bombardment. There he announced, “I am Colonel Wigfall,” and, with no authorization, urged its surrender. Confusion ensued when an official Confederate delegation showed up and also demanded surrender. But the fort was ready to capitulate. Wigfall returned to shore, where he waved his hat and shouted from his boat, “Sumter is ours!”

Mary Todd Lincoln, 42, was the president’s wife. Reared in Kentucky, she had relatives in the Confederate army but was devoted to her husband. Refined, high-strung and needy, she would become one of Washington’s most tragic and fragile figures, losing first a son, then her husband and, at times, her mind during her four-year sojourn in the White House.

Adam J. Slemmer, 43, was the now almost-forgotten U.S. Army lieutenant in command of Fort Pickens, Fla., which was also menaced by the Confederates in 1861. The diminutive, bespectacled Pennsylvanian took an aggressive stand against the enemy, rejecting surrender demands and almost daring the rebels to attack. The fort remained in Union hands throughout the war.