This Destructive War: The British Campaign in the Carolinas, 1780-1782

You desperately need to read an actual book, or maybe two. I recommend The Southern Strategy and This Destructive War. The latter covers the information you need about Greene, but the first covers the years leading up to Greene taking over in the Carolinas and sets the context. Basically, without Greene there is no Yorktown. After Gen. Gates' disastrous defeat at the Battle of Camden, the American forces in the South were in disarray. Washington sent Greene down to restore the situation. Greene drew Cornwallis out of South Carolina in a fighting retreat, wearing his forces down in numerous skirmishes. He finally turned to give battle at Guilford Courthouse, and although he was forced to yield the battlefield, he absolutely mauled Cornwallis's army. Cornwallis was forced to retreat to Wilmington in hopes of being resupplied and reinforced. Cornwallis then relocated to Yorktown, while Greene marched back down into South Carolina and undid everything Cornwallis had achieved before being drawn north. It was a brilliant accomplishment.