George Washington was always concerned about spies. They were a constant problem except when the armies were on the move. He knew he could not stop all of them, so feeding them false information was his next best defense. With that in mind on December 12, 1776, he told Colonel John Cadwalader of the Philadelphia Associators of the Pennsylvania militia, “Keep a good look out for spies; endeavor to magnify your numbers as much as possible.” It was a ploy he would use over and over again in creating false troop information, inflating the size and giving the wrong location of his forces for spies to discover and take back to enemy headquarters.

Washington in December of 1776 was desperate to know what the British were doing. Spare no pains or expense to get intelligence of the enemy’s intentions, Washington told Cadwalader. He had also told General James Ewing, “Spare no pains nor cost to gain information of the enemy’s movements and designs. Whatever sums you pay to obtain this end I will cheerfully refund. “He also advised Brigadier General Philemon Dickinson to spare no pains or expense to obtain intelligence, and all promises he made or monies advanced would be acknowledged and paid. Three days later Washington was still desperate for information and again was encouraging Cadwalader to get intelligence of the enemy’s intentions.

Dickinson, who was at Yardley’s farm in Bucks County, Pennsylvania, advised Washington on the 21st of the information he was able to collect from two people who had come out of New Jersey on what was going on in New Brunswick, and from a person from Crosswicks regarding boats at Lewis’s Mill. A slave from Trenton told of boats being built a mile from town. Dickinson told Washington he was going to increase the amount he was offering to $15 or $20 for someone to go as a spy to Trenton and return. “People here are fearful of the inhabitants betraying them.” On the 24th he was able to secure someone to take the risks and he got him across the river into New Jersey. He was due back the next morning, at which time he was going to be provided with a horse to get to Washington.

On the morning of December 31, 1776, while at Crosswicks, one of Cadwalader’s spies, who was identified only as “a very intelligent young gentleman,” had just returned from the British camp at Princeton some sixteen miles distant. He identified the number and locations of British and Hessian forces in the town. He said “there were about five thousand men, consisting of Hessians and British troops—about the same number of each. . . . He conversed with some of the officers, and lodged last night with them.” As part of a disinformation campaign, Washington had previously instructed that the numbers of American troops were to be magnified. The spy complied with these instructions by saying that Washington had 16,000 men. However, they would not believe that Washington had more than 5,000 or 6,000. The spy reported, “They parade every morning an hour before day [break]—and some nights lie on their arms—An attack has been expected for several nights past—the men are much fatigued, and until last night [were] in want of provisions—when a very considerable number of wagons arrived with provisions from [New] Brunswick.” He provided a crucial piece of information: the enemy was not expecting an attack from the east, as there were “no sentries on the back or east side of the town” facing the water, thus leaving the town unguarded. The spy also provided enough detailed information for a map, which was made by Cadwalader, showing the enemy’s positions at Princeton.

Washington and the army re-crossed the ice-choked Delaware and returned to New Jersey on December 29. The artillery was unable to cross till the 31st due to the ice. When assembled at Trenton, Washington’s forces numbered 6,000 men and forty cannons. However, enlistments were expiring and soldiers would be going home. The army was going to evaporate before his eyes. Washington appealed to his men to stay in service for some promised bonus money. On December 31, Robert Morris in Philadelphia sent Washington the sum of 410 Spanish milled dollars, 2 English crowns, 10½ English shillings, and one half a French crown, amounting to 155 pounds, 9 shillings, 6 pence in Pennsylvania currency, or 124 pounds, 7 shillings, 8 pence lawful money, which is the value in gold and silver. Buoyed by the combination of victory at Trenton and money from Morris, most men stayed.

After Washington’s victory at Trenton, British General Cornwallis returned to New Jersey from New York City. He assembled a force of 8,000 at Princeton, leaving 1,200 at Princeton under the command of Lieutenant Colonel Charles Mawhood of the 17th Regiment of Foot. On January 2, he took his remaining forces, which included twenty-eight cannons, and marched toward Trenton and Washington’s army. When he reached Maidenhead (now Lawrenceville), he detached Colonel Alexander Leslie of the 64th Regiment of Foot with 1,500 men. He ordered them to stay there until the next morning. As soon as Washington heard that Cornwallis was on his way to attack him, he detached men to skirmish with the approaching British forces in a delaying action. Due to the American resistance it was not until late in the day when the British army finally reached Trenton. It was the second time in eight days that the Americans would engage the enemy.

The Americans were encamped on the east side of a bridge across the Assunpink Creek. The British advanced in solid columns onto the bridge. The Americans fired in unison and the British fell back. The British regrouped and charged the bridge again. This time the Americans fired a cannon into the redcoats and they fell back once more. After regrouping they moved onto the bridge. This time the American cannons fired antipersonnel canister shot, which is like a shotgun blast of small pellets. The bridge was littered with the dead. A soldier described the scene: “The bridge looked red as blood, with their killed and wounded and their red coats.” The firing and the killing continued till sunset when Cornwallis called off the attack. He planned to take the bridge the next morning and then crush Washington and the Continental Army. Both sides were exhausted and the soldiers on both sides were ordered to rest.

It was brought to Washington’s attention that the British could cross the creek farther down at Philip’s Ford and turn his flank. He would have been caught between the British forces and the Delaware River. It would have been a repeat of the Battle of Long Island. This time he could not escape by crossing the Delaware, as he had crossed the East River before, as his vessels were farther upstream. He did not have the time for them to be brought to his rescue. Later the British quietly, under the cover of darkness, began moving 2,000 men in the woods into position to cross Philip’s Ford in the morning.

Washington had received Cadwalader’s spy’s intelligence on the enemy situation at Princeton. The unknown spy provided great detail of the British fortifications. This would be the rare occasion that Washington acted on a single spy’s intelligence, as there was no time to get corroborating intelligence. Because of the desperate situation, he could not stand pat. He had to do something or be destroyed.

He hurriedly called a council of war. It was decided to slip away during the night and surprise the British at Princeton. The Continental Army’s military and personal baggage was sent south to Burlington. The artillery was wrapped in heavy cloth to quiet the noise. Five hundred soldiers were left at Trenton with two cannons. Some were assigned to tend the campfires to keep them burning. Others were to make noise digging with picks and shovels to convince the British that the American army was going to make a stand and was reinforcing its position preparing for the British attack at Philip’s Ford. The soldiers who were left as a distraction were to sneak away during the night and catch up to the Continental Army before dawn. The army, as silently as possible, slipped away beginning at 2 a.m. while the British watched the light from the American camp- fires. For some of the men it would be their third night march in a row in the cold and extreme darkness. They were slowed by the task of getting the artillery over stumps in the frozen, rutted road. After crossing the new bridge, Washington split the army into two units just as when he approached Trenton a week earlier. Unfortunately, just like a week earlier, they were arriving later than intended and lost the cover of darkness.

Thirty-four-year-old Rhode Islander General Nathanael Greene took the smaller column of soldiers and went west to take control of the main road from Princeton to Trenton. They were to keep the enemy at Princeton from escaping and block any reinforcements coming to the aid of those at Princeton. General John Sullivan of New Hampshire commanded the main body of the army of 5,000 men. They went to the right along the Saw Mill Road.

Cornwallis had ordered forty-seven-year-old Lieutenant Colonel Charles Mawhood to bring the 17th and 55th British Regiments of Foot along with some artillery to Trenton to join his army in the morning. Mawhood marched out from Princeton at about five in the morning. While on the march he sighted the main American army under General Sullivan. He immediately sent a rider to warn the 40th Regiment of Foot in Princeton of the advancing Americans.

Mawhood decided to attack with 450 men the main American army. Brigadier General Hugh Mercer’s 1,500 men of Greene’s division made the first contact with Mawhood’s men in William Clark’s orchard. Lieutenant William John Hale of the 45th Regiment of Foot wrote that the American volley was “a heavy discharge, which brought down seven of my platoon at once, the rest being recruits, gave way.” He continues, “I rallied them with much difficulty, and brought them forward with bayonets.” The two sides matched volley for volley. Pools of blood glistened on the ice-covered field. Mawhood saw an opportunity and ordered a bayonet charge against the American riflemen, who did not have bayonets. Brigadier General Mercer’s horse was hit and down Mercer went as he ordered a retreat. His men safely retreated but Mercer fell into British hands. He fought with his sword and was bayoneted many times and would die several days later. His men retreated right into Colonel John Cadwalader’s Pennsylvania Associators as they were trying to deploy. Washington came on the field and rallied the men, riding on a white horse within seventy-five feet of the British line. He made a very easy target but somehow came through the battle without a scratch. More American units came onto the field, some with bayonets drawn.

The British fired a volley that went over the heads of the Americans. Washington with the army under control then ordered a platoon to fire as it marched forward. Washington was turning their flank and was about to attack the British rear as well as the front and flank. The circle was closing. The British decided their only course of action was either to fight and be cut to pieces or retreat through the only way still available. Mawhood sent the artillery back to Princeton in an effort to save them. The 55th Regiment of Foot took up position south of the town at a place called Frog Hollow. They were outnumbered 10 to 1. They did some delaying actions, falling back to new defensive positions. This bought the British some time to remove as much of their supplies and artillery out of Princeton as possible and take them to safety in New Brunswick. When the American army was within fifty or sixty feet of the British defenses and ready to charge, a British officer with a white handkerchief on the point of his sword asked for a truce in order to surrender. General Sullivan accepted his surrender.

Some of the British forces that were in the town took shelter in Nassau Hall, which was the main building for the College of New Jersey (now Princeton). Alexander Hamilton had some cannons brought to the front of Nassau Hall and fired at the building. When some Americans broke open the front door, the British waved a white flag through one of the windows and surrendered. The Americans had defeated the British regulars and were now in control of the town. As soon as Cornwallis realized the Americans had slipped away during the night, were now behind him, and he was in an unsupported position, he and his troops headed back to Princeton.

The British payroll chest of £70,000 lay just sixteen miles up the road in New Brunswick guarded by a skeleton force. It was a great prize but Washington’s men were exhausted. Some had not had any rest for two nights and a day. From the best intelligence Washington was able to get, the British were so alarmed at the possibility of an attack at New Brunswick that they immediately marched there without halting at Princeton. This allowed Washington to take his men unmolested another thirty miles past New Brunswick to the safety of an encampment in the Watchung Mountains in and around Morristown.

The increase in the morale of the public and the troops was meteoric. The mood went from the despair of expecting Philadelphia to fall to the British juggernaut, which had ridden rough-shod over New York and New Jersey, to euphoria over the two American victories. William Hooper, a Continental congressman from North Carolina, best described the change in the public morale and the heady confidence in Washington and the Continental Army after the victories at the Battle of Trenton over the Hessians and the Battle of Princeton over the British.