The Battle of Monmouth, also known as the Battle of Monmouth Court House, was fought near Monmouth Court House in modern-day Freehold Borough, New Jersey, on June 28, 1778, during the American Revolutionary War. It pitted the Continental Army, commanded by General George Washington, against the British Army in North America, commanded by General Sir Henry Clinton. It was the last battle of the Philadelphia campaign, begun the previous year, during which the British had inflicted two major defeats on Washington and occupied Philadelphia. Lee, Washington’s second-in-command, advised awaiting developments as he did not wish to commit the American force against the British regulars. However, Washington determined that the British column was vulnerable to attack as it traveled across New Jersey with its baggage train, and moved from Valley Forge in pursuit. Washington was still undecided how to attack the British column, and held a council of war. The council, however, was divided on the issue; with a small group of officers including Brigadier General Anthony Wayne urging a partial attack on the British column while it was strung out on the road. Lee was still cautious, advising only harassing attacks with light forces. On the afternoon of June 27, Washington conferred with the vanguard's senior officers at Englishtown but did not offer a battle plan. The first shots were exchanged around 08:00 in an entirely American skirmish between a small detachment of Rangers and Dickinson's militia. Grayson arrived just in time to deploy his troops in support of the militia near a bridge over a ravine and watch the Rangers withdraw.

The bridge was on the Englishtown–Monmouth Court House road and spanned the Spotswood Middle Brook, one of three ravines bordered by marshy wetlands or 'morasses' that cut through what would soon become a battlefield. Once the vanguard was concentrated at the bridge, Lee replaced Grayson with Wayne to command the approximately 550-man lead element, which comprised detachments led by Colonel Richard Butler, Colonel Henry Jackson and Grayson, supported by four artillery. As soon as he received news that his rearguard was being probed, Clinton ordered Cornwallis to march the first division back towards Monmouth Court House. The main body had reached Englishtown at 10:00, and by noon it was still some four miles from Monmouth Court House. As Lee and Wayne fought south of the Spotswood Middle Brook, Washington was deploying the main body on Perrine's Hill, northwest of the bridge across the brook. Clinton had lost the initiative. He saw no prospect of success assaulting a strong enemy position in the brutal heat, and decided to break off the engagement. While the battle was raging, Knyphausen had led the baggage train to safety. His second division covered by the Hessian Jägers under Lieutenant Colonel Wurmb endured only light harassment from militia along the way, and eventually set up camp some three miles from Middletown. Though Washington had failed to destroy the British column, he had inflicted damage to their troops, and proved that American troops, if properly led, could stand against the British regulars. The British had defended their baggage train, but were unable to defeat the Americans in open battle.