At his Hornwork headquarters, GeneralLincoln struggled to oversee the city’s defenses while dealing with Lt. Gov. Christopher Gadsden, the state’s Privy Council and hundreds of trapped civilians. The Council had sorely tried Lincoln’s patience with contradictory demands for resistance and a negotiated surrender. Clinton’s patience had been equally tested by the stubborn American resistance, and he ordered an indiscriminate bombardment of Charleston after Lincoln insisted on a surrender only with the honors of war for his Continentals. Civilian morale in the city collapsed as a result, compelling Lincoln to accept Clinton’s surrender terms on 11 May 1780: Continentals imprisoned with no honors of war and no property guarantees for the Charlestonians–although Clinton grudgingly agreed to parole the American militia. Lincoln and some 1,800 able-bodied Continentals, with their colors cased, surrendered in front of the Hornwork on 12 May 1780. In exchange for some 270 casualties, the British had captured Charleston and about 5,600 American prisoners–encompassing twenty-three Continental regiments from four states plus hundreds of Continental Navy personnel–thousands of weapons, 300 cannons, tons of ordnance stores, and the entire naval flotilla. Ironically, a powder magazine explosion, triggered when soldiers carelessly stacked captured American muskets, caused more casualties than was incurred during the siege. The Continental officers were quickly exchanged, while the soldiers were offered freedom in exchange for enlisting in the King’s army. Most rejected the offer and were eventually locked up on prison ships in the harbor. British control was lax initially and several hundred Americans escaped captivity, but many more died from sickness or starvation during their incarceration.
"This I laid before a Council of General & field officers & the Captains of the Continental ships—It was the view of the Council, that terms of capitulation ought to be proposed—Terms were accordingly sent out but as so many of them were rejected...hostilities again commenced in the evening of the Ninth [May] with a more incessant and heavy fire than ever, which continued until the 11th when having prior thereto received an address from the principal inhabitants of the town, and a number of the country militia signifying that the terms acceded to by General Clinton...were satisfactory and desired that I would propose my acceptance of them, and a request from the Lieutenant Governor and Council that the negotiations might be renewed—the militia of the Town having thrown down their arms—our provisions, saving a little rice, being exhausted—The troops on the lines being worn down with fatigue...Our harbour closely blocked up—compleatly invested by land by nine thousand men at least the flower of the British army in America, besides the large force which, at all times, they could draw from their marine, and aided by a great number of blacks, in all their laborious employments—The garrison at this time, exclusive of the sailors, but little exceeding twenty five hundred men, part of whom had thrown down their arms—The citizens in general discontented and clamorous——The enemy being within twenty yards, of our lines, and preparing to make a general assault by sea and land—many of our cannon dismounted and others silenced from the want of shot—A retreat being judged impracticable, and every hope of timely succour cut off, we were induced to offer and accede to the terms executed on the 12th. A copy of them, the several letters and propositions that passed between Sr Hy Clinton & myself from the 10th of April to the 12th of May, I do my self the honor to inclose. Thus, sir, in as concise a manner as possible, and perhaps too much so in justice to myself, I have given to your Excellency a state of matters, relative to the defence and loss of Charles town, & the measures pursued by me for its safety."
Maj. Gen. Benjamin Lincoln to Gen. George Washington, 11 August 1780Founders Online, National Archives, https://founders.archives.gov/documents/Washington/99-01-02-02900.