Cornwallis takes Charleston

The city of Charleston, South Carolina, had always been a tough objective for an enemy, as Lord Cornwallis had already found in 1776, but the general was eager to try again. Cornwallis had long despised the hit-and-run strategy that Henry Clinton had been employing, and in the fall of 1779 he sold his commander in chief on a masterplan for the conquest of the entire South. An amphibious expedition against Charleston would be followed by the conquest of both Carolinas with the help of local Loyalists; and a joint military and naval campaign would then secure Virginia and Chesapeake Bay. With the thirteen states reduced to nine, American independence would seriously be hampered, if not destroyed.
The Southern masterplan opened promisingly for Great Britain. In January 1780, Clinton, with Cornwallis his second in command, embarked 8,500 troops at New York. They landed on Johns Island, thirty miles south of Charleston, and began a leisurely overland march on the city, while his fleet of fourteen warships confined themselves to blockading the city from well off shore.
General Benjamin Lincoln, instead of falling back into the interior where Clinton would have to follow him, shut himself behind the works of Charleston, and with that decision gave up his prime advantages of mobility and knowledge of the terrain. Instead his Southern army, barely 5,000 strong, largely green and disorganized, was now being besieged by trained British troops, supported by a fleet.
The outcome was predictable. Clinton drew his lines tighter and tighter, while his ships crashed through the fire of Fort Moultrie and entered Charleston harbor. On May 12, Lincoln was forced into an unconditional surrender that turned his 5,000 Continentals and militia into prisoners of war. Huge quantities of supplies were lost, and nearly all the Patriot leaders of South Carolina, political and military, were seized, except for Governor Rutledge, whom Lincoln managed to slip out of the city. The American cause had suffered the severest disaster of the entire Revolutionary War.