 On the night of January 2 , 1777 George Washington , Commander @-@ in @-@ Chief of the Continental Army , repulsed a British attack at the Battle of the Assunpink Creek in Trenton . That night , he evacuated his position , circled around General Lord Cornwallis ' army , and went to attack the British garrison at Princeton . Brigadier General Hugh Mercer of the Continental Army clashed with two regiments under the command of Lieutenant Colonel Charles Mawhood of the British Army . Mercer and his troops were overrun and Washington sent some militia under Brigadier General John Cadwalader to help him . The militia , on seeing the flight of Mercer 's men , also began to flee . Washington rode up with reinforcements and rallied the fleeing militia . He then led the attack on Mawhood 's troops , driving them back . Mawhood gave the order to retreat and most of the troops tried to flee to Cornwallis in Trenton . 
