To camouflage the nighttime retreat, which would start after midnight, Washington reprised the same repertoire of tricks he had applied on Long Island. The wheels of the artillery were wrapped in rags to deaden sounds. Campfires were kept burning to foster the illusion of an army settled in for the night. Loud noises were broadcast with entrenching tools, as if the Americans were digging in for violent reprisals the next day. Again the troops were kept unaware of their destination. In fact, Washington stole away with such artful stealth, wrote one officer, that “the rear guard and many of his own sentinels never missed him.”⁴⁹ In marching twelve miles through the night toward Princeton, Washington pushed his long-suffering men almost beyond human endurance. It was a long, harrowing march down dark country lanes congealed with ice. The weary men, wrapped in a numb trance, some barely awake, padded against stinging winds; many fell asleep standing up whenever the column halted.

The troops arrived at the college town later than scheduled, shortly after an exceptionally clear, beautiful dawn that James Wilkinson remembered as “bright, serene, and extremely cold, with a hoarfrost that bespangled every object.”⁵⁰ The men rapidly repaired a bridge over Stony Brook, south of town, before the army divided into two groups: Sullivan’s division veered northeast while Greene’s moved due north. The first spirited fighting erupted unexpectedly. Lieutenant Colonel Charles Mawhood was about to rush two British regiments to Trenton to aid Cornwallis when, to his infinite surprise, he encountered American forces under General Hugh Mercer in a broad, rolling meadow. “I believe they were as much astonished as if an army had dropped perpendicularly upon them,” declared Knox.⁵¹ Mawhood ordered a ferocious bayonet charge that staggered Mercer’s men. Mercer himself was knocked off his horse and given a merciless drubbing as he lay on the ground. In capturing the dapper, handsome Mercer—a physician from Fredericksburg and a friend of Washington’s—the British imagined they had taken the commander in chief himself. “Call for quarters, you damned rebel,” they taunted him. To which Mercer retorted, “I am no rebel,” and slashed at them with his sword. ⁵² The British mauled him repeatedly with their bayonets, carving seven gashes, until he lay near death. For Washington, it was a disturbing preview of the fate awaiting him if ever he were captured.

The Battle of Princeton gave Washington another chance to show that he was the army’s chief warrior in the antique sense. The eighteenth-century battlefield was a compact space, its cramped contours defined by the short range of muskets and bayonet charges, giving generals a chance to inspire by their immediate presence. When Mercer’s men began to retreat, harried by redcoats flashing bayonets, General Greene directed Pennsylvania militia into the fray, only to have them collide with Mercer’s fleeing men amid “a shower of grapeshot.”⁵³ The American panic was stemmed by Washington himself, who suddenly circled into view and exhorted his rattled men to stand and fight. “Parade with us, my brave fellows!” he exclaimed, waving his hat. “There is but a handful of the enemy, and we will have them directly.” ⁵⁴ According to his aide-de-camp Colonel John Fitzgerald, Washington rallied the men with an act of unbelievable bravery: he reined in his horse, faced the enemy directly, and simply froze. Yet again the intrepid Washington acted as if he were protected by an invisible aura.

With the British entrenched beyond a hillside fence, Washington lengthened and strengthened the patriot line, instructing his men not to fire until told to do so. He exhibited exceptional sangfroid as he rode along the line. Then he personally led the charge up the hill, halting only when they had pushed within thirty yards of their adversaries. As he issued the command to fire, Washington, on his white charger, was such a conspicuous target that Fitzgerald clapped his hat over his eyes because he couldn’t bear to see him shot. When the fusillade of bullets ended and the enemy scattered, Fitzgerald finally peeked and saw Washington, untouched, sitting proudly atop his horse, wreathed by eddying smoke. “Thank God, your Excellency is safe!” Fitzgerald said to him, almost weeping with relief. Washington, unfazed, took his hand fondly. “Away, my dear colonel, and bring up the troops. The day is our own!”⁵⁵ Fitzgerald wasn’t the only one bowled over by Washington’s coolness. “I shall never forget what I felt . . . when I saw him brave all the dangers of the field and his important life hanging as it were by a single hair with a thousand deaths flying around him,” wrote a young Philadelphia officer. “Believe me, I thought not of myself.”⁵⁶

Washington spurred his horse after the retreating enemy, for once giving way to pure exhilaration. Perhaps repaying the old insult from the Battle of Harlem Heights, he shouted to his men, “It’s a fine fox chase, my boys!”⁵⁷ Whatever joy he felt, however, was tempered by the horrifying spectacle of a snowy battlefield stained with American blood. One officer lay “rolling and writhing in his blood, unconscious of anything around him.”⁵⁸ An adolescent lieutenant had a bullet hole in his chest and a skull smashed in by a bayonet. And so on.

In the battle’s concluding chapter, two hundred British troops sought asylum in the principal college building, Nassau Hall. According to legend, Alexander Hamilton deployed his artillery against the building and decapitated a portrait of King George II with a cannonball. By the time a white flag of surrender popped from a window, the victorious Americans had inflicted more than five hundred casualties and taken between two hundred and three hundred prisoners; only about three dozen Americans were killed in the one-sided battle. To Washington’s dismay, his soldiers, avid for booty, ransacked Nassau Hall and dragged out food, clothing, furniture, and even paintings. They also fleeced uniforms from British corpses on the battlefield. To stop this plunder, Washington had the field cordoned off by sentries. He also accompanied two wounded redcoats to private homes, where American surgeons treated them and performed amputations. In his humane treatment of prisoners, Washington wanted to make a major statement, telling one officer that British captives should “have no reason to complain of our copying the brutal example of the British army in their treatment of our unfortunate brethren.”⁵⁹

The consecutive victories at Trenton and Princeton resurrected American spirits, especially since the Continental Army had scored an undisputed victory over British regulars. The psychology of the war was dramatically reversed, with the once-dominant British presence in New Jersey “reduced to the compass of a very few miles,” in Washington’s view.⁶⁰ By rolling back British gains, he undercut the Crown’s new strategy of securing territory and handing out pardons. Nathanael Greene estimated that the Americans had killed or captured up to three thousand enemy soldiers in a two-week stretch. Although Washington wanted to proceed to New Brunswick and raid a major storehouse of British supplies, his men hadn’t slept for two days, and he didn’t believe he could press them further.

The back-to-back victories had also changed the calculus of the war. Henceforth the British would have to conquer the colonists, not simply cow them into submission. The Americans, having bounced back from near despair, now showed an irrepressible esprit de corps. “A few days ago, they had given up the cause for lost,” scoffed the Loyalist Nicholas Cresswell. “Their late successes have turned the scale and now they are all liberty mad again.”⁶¹ “Four weeks ago, we expected to end the war with the capture of Philadelphia,” said the Hessian captain Johann Ewald, “and now we had to render Washington the honor of thinking about our defense.”⁶²