[A somewhat fanciful depiction of The Siege of Charleston from the British lines by Alonzo Chappell, 1862.]
On May 12, 1780, Charleston, South Carolina surrendered to a British army under the command of Sir Henry Clinton. It was the worst Patriot defeat in the American War for Independence. Clinton not only took the city, the most important in the South, he also captured most of the garrison, more than 5000 soldiers. It was not until the Surrender at Bataan in World War II that more American soldiers surrendered to an enemy army. [Image: Sir Henry Clinton]
The victory was the culmination of a campaign that had begun three months before, when Clinton had disembarked an army of more than 8000 men on Simmons (now Seabrook) Island. Marching through the difficult terrain of Simmons and James Islands, they crossed the Ashley River onto Charleston Peninsula on March 29.
They immediately began to construct siege lines that moved them and their artillery ever closer to the city. The map below shows the gradual encroachment of the British lines.
Thousands more British and Loyalist soldiers from Savannah and New York soon joined Clinton, as did thousands of black runaways attracted by his promise of freedom. Many of them were enlisted as Black Pioneers, auxiliaries to the British Army.
The American commander, Benjamín Lincoln of Massachusetts, had advocated Colonel John Laurens' idea of arming enslaved men on the same promise. The state legislature voted the proposal down by a large majority. Some local leaders argued that allowing the British a free passage through South Carolina was preferable to the prospect of arming Africans.
By late April the British had completely surrounded Charleston. Lincoln proposed to escape with his army before the British had encircled the city. He backed down in the face of local hostility to the move. [Image: Benjamin Lincoln]
Acting Governor Christopher Gadsden (of "Don't Tread On Me" flag fame) led an angry crowd to Lincoln's headquarters. Gadsden accused Lincoln of cowardice. One of his entourage threatened to open the gates to the enemy and attack Lincoln's soldiers before they could get to their boats. [Images: Christopher Gadsden and his flag]
Most of Lincoln's officers also opposed a withdrawal at this point. Lincoln agreed to remain. In the end, cut off from escape and reinforcements, running out of food, and under increasingly heavy bombardment, he accepted Clinton's terms. Ironically, Gadsden and others who had accused Lincoln of cowardice earlier now demanded he surrender to save the city from destruction.
Under Clinton's terms, the Continental soldiers became prisoners of war. They were interned in and around the city. The militia were paroled. They could go home, as long as they did not take up arms against the British. Lincoln, Laurens, and other officers were also paroled not long after. They were able to return to active service after being exchanged for British prisoners of equivalent rank.
A few weeks later, Clinton returned to his headquarters in New York. He left General Lord Cornwallis in command in the South. The two men despised each other, a fact that would cause serious problems for British operations for the rest of the war. [Image: General Charles, Lord Cornwallis]
Before leaving, Clinton made a serious mistake. He decreed that men who had taken parole had to swear an oath of allegiance to the Crown. In effect, they might have to fight for the British against their former comrades.
Anger at Clinton's proclamation helped fill the ranks of the partisan forces that soon emerged in the backcountry under Francis Marion and Thomas Sumter. Cornwallis won a decisive victory over General Gates at Camden in August, but his inability to subdue the partisans (and Carolina fevers) led him to march his army to Virginia and Yorktown.
Footnote: On the same day Charleston surrendered to Clinton, an enormous tragedy occurred. As the Patriots were surrendering their weapons at the powder magazine (on Magazine Street), the powder exploded, killing scores and injuring hundreds. The dead and wounded included soldiers from both sides, women from a nearby brothel, and most of the "lunatics" at the adjacent poorhouse and hospital. Each side blamed the other, but the explosion was most likely caused when a soldier threw down a musket that had not been unloaded and discharged into the magazine.
Carl P. Borick, A Gallant Defense: The Siege of Charleston, 1780. Columbia: University of South Carolina Press, 2003.