 Cornwallis returned to America in July 1779, where he was to play a central role as the lead commander of the British "Southern strategy". At the end of 1779, Clinton and Cornwallis transported a large force south and initiated the second siege of Charleston during the spring of 1780, which resulted in the surrender of the Continental forces under Benjamin Lincoln. Cornwallis and Clinton at first worked closely together during the siege, but their relationship deteriorated. Cracks had formed between the two as early as October 1776, when Cornwallis reported to General Howe critical comments that Clinton made about Howe's conduct at White Plains. Clinton also seemed to believe that one reason for Cornwallis's trips to England was to scheme for an independent command. Cornwallis as second in command held a dormant commission and would replace Clinton as commander in chief. He was aware that Clinton wanted to resign, but he did not want to be saddled with a difficult command situation should that occur. Cornwallis consequently avoided advising Clinton as much as possible, in order to avoid responsibility for poor outcomes. The deterioration in their relationship set the stage for some of their communication difficulties that resulted in Cornwallis's eventual surrender at Yorktown. In late April, Clinton detached a force under Cornwallis to ensure that the enemy's communications and supplies were interrupted around the city. Because of this, Cornwallis missed most of the siege bombardment and the surrender in May; forces directed by Cornwallis and led by Banastre Tarleton completed the encirclement of Charleston, skirmishing with the Americans at Monck's Corner and Lenud's Ferry. After the American surrender Clinton ordered Cornwallis to secure South Carolina's interior, while Clinton organized control of Charleston. Not long after Tarleton defeated Abraham Buford's Virginia regiments at Waxhaw, Clinton returned to New York, leaving Cornwallis in command in the south.
