The Battle of Mamaroneck (also known as the Skirmish of Heathcote Hill) was a skirmish in the New York and New Jersey campaign of the American Revolutionary War fought on October 22, 1776, at Mamaroneck, Westchester County, New York. Mamaroneck, the Native American name meaning the place where the sweet waters fall into the sea, is located just twenty-three miles north of New York City at the mouth of the Mamaroneck River that forms a harbor. John Richbell, a London merchant living in Oyster Bay, Long Island, purchased the land in 1661 from the local Siwanoy Indians for a supply of tools, kettles ,and clothing. The village was small and the surrounding lands were forested, dotted with stretches of tilled fields and pastures that had been cleared by farmers. Following the retreat of George Washington's army to White Plains, British General William Howe landed troops in Westchester County, intending to cut off Washington's escape route. To cover the eastern flank of his army, Howe ordered Major Robert Rogers and his Rangers to seize the village of Mamaroneck which had been recently abandoned by the Continental army. On the night of October 22, 750 men under Colonel John Haslet attacked the British encampment. Haslet's men achieved complete surprise, but Rogers' Rangers rallied and drove off the attackers. Haslet attacked at four a.m. on October 22. On the outskirts of Rogers’s camp, Major Green’s vanguard dispatched a struggling Indian sentinel with a sword thrust.

Matters became complicated when Green stumbled upon an exterior guard of sixty men under Capt. John Eagles. Having thought better of his earlier decision to leave the area unguarded, Rogers had repositioned this group between Heathcote Hill and where the farthest sentinel was stationed. When Green’s band called on Eagles to surrender, some in his squad offered to submit but others resisted. Although Haslet’s main body surrounded the opposing guards, confusion reigned in the dark as the two sides became entangled and in some cases soldiers struggled with their own. In the confusion, Eagles and about a third of his men fell back to their main camp, while the rest were overpowered. By now, the main body of rangers had been alerted and most of Haslet’s guides had deserted or could not be found. The colonel led his troops toward the Loyalist camp on Heathcote Hill, but Rogers was able to rally his regiment and halt the Continentals’ advance. The advantage of surprise gone, Haslet opted to withdraw and settle for an incomplete victory rather than storm a strongly-held position in the dark against an unknown number of men. Even though Rogers displayed excellent leadership under fire, this action was considered a defeat for the British and proved to be Rogers’ last command under fire. Howe and his subordinates took note of the criticism lobbied against Rogers and no longer tolerated his alcoholism.