When 3 January 1777
Strength British – 1,200
Americans – 4,500
After, the attack on Trenton, the British – led by General Lord Charles Cornwallis and Major General Grant – in Princeton with 8,000 troops, planned to advance on Washington’s force and prevent him from making any further attacks on British outposts in New Jersey.
Following the attack on Trenton, Washington withdrew to the west bank of the Delaware River. He intended to return within a few days to attack more British outposts with the hopes of forcing the British completely out of New Jersey.
On 2 January, General Lord Cornwallis advanced with 5,500 British troops towards Trenton, leaving behind two smaller forces in Princeton and Maidenhead. As Cornwallis moved ahead, Washington sent troops to skirmish with them to delay their advance so it was almost nightfall by the time the British reached Trenton. They attempted to cross the Assunpink River three times but American resistance was too strong, so Cornwallis put off the crossing until morning.
Washington decided to move his army before it was attacked and overwhelmed the next day. In the middle of the night, leaving 500 soldiers behind to keep the campfires burning, he circled around Cornwallis' army, and went to attack the British garrison at Princeton.
On 3 January, Brigadier General Hugh Mercer of the Continental Army clashed with two British regiments under the command of Lieutenant Colonel Charles Mawhood of the British Army. Mercer and his men were overrun, and Mercer was mortally wounded by charging redcoats. Washington sent a brigade of militia under Brigadier General John Cadwalader to help them. The militia, on seeing Mercer's men running away, also began to flee. Washington rode up with reinforcements and rallied the retreating men. He then led the attack on Mawhood's troops, driving them back. Mawhood gave the order to retreat and most his men tried to flee to Cornwallis in Trenton.
In Princeton itself, Brigadier General John Sullivan encouraged some British troops who had taken refuge in Nassau Hall to surrender, ending the battle. After the battle, Washington moved his army to Morristown, and with their third defeat in 10 days, the British decided to leave southern New Jersey.
The British viewed Trenton and Princeton as minor American victories, but with these victories, the Americans believed they could win the war and the French began to take an interest in supporting the American cause.
British – 40 killed / 58 wounded / 187 missing
Americans – 23 killed / 20 wounded
The Death of General Mercer at the Battle of Princeton by John Trumbull.