Greene divided his army, leading his main force southeast pursued by Cornwallis; a detachment was sent southwest under Daniel Morgan, who defeated Tarleton's British Legion at Cowpens on January 17, 1781, nearly eliminating it as a fighting force. The Patriots now held the initiative in the south, with the exception of a raid on Richmond led by Benedict Arnold in January 1781. Greene led Cornwallis on a series of counter marches around North Carolina; by early March, the British were exhausted and short of supplies and Greene felt strong enough to fight the Battle of Guilford Court House on March 15. Although victorious, Cornwallis suffered heavy casualties and retreated to Wilmington, North Carolina seeking supplies and reinforcements.