The Beverley Robinson House stood on the east bank of the Hudson opposite West Point, near the foot of Sugar Loaf Mountain. Built around 1758 for Beverley Robinson and his wife, Susanna Philipse Robinson, it occupied a commanding position within the Hudson Highlands. Robinson remained loyal to the Crown, helped raise the Loyal American Regiment, and lost control of the estate as revolutionary authorities confiscated Loyalist property.

The seized house became useful to American commanders responsible for the Highlands. George Washington, Israel Putnam, Benedict Arnold, and other officers used it at different times as headquarters or lodging. Its position linked river traffic, roads, ferries, and the defensive complex at West Point. Holding the Highlands prevented British forces based around New York City from moving freely up the Hudson and separating New England from the other states.

In 1780 Washington placed Arnold in command of West Point. Arnold, resentful over money, promotion, and criticism, was already communicating secretly with the British. From the Robinson House he controlled access to plans, troop dispositions, supply information, and orders affecting the fortress. He proposed delivering West Point to the enemy, a betrayal that could have opened the river corridor and dealt a severe political and military blow to the American cause.

British intelligence officer Major John André met Arnold and carried papers describing the defenses, but American militiamen captured him near Tarrytown. On September 25, Arnold received warning at the Robinson House that André had been taken. Washington was approaching for a planned breakfast and inspection. Arnold abruptly left the table, rode to Beverley Dock, and escaped downriver to the British sloop Vulture before his treason was fully understood.

Washington arrived to find Arnold absent and soon received the captured papers. The conspiracy failed, West Point remained American, and André was later executed as a spy. Arnold entered British service and led raids against the country he had once defended. The house consequently became inseparable from the drama of his betrayal, although its history also includes the Loyalist family displaced from it and the many American commanders who used the property.

The Robinson House was destroyed by fire in the late nineteenth century, and the marker indicates its former location rather than a surviving headquarters. Landscape and documentary evidence must reconstruct the relationship among house, dock, river, and fortress. The site’s significance lies in that geography: a confiscated Loyalist mansion became the headquarters from which an American general tried to surrender West Point and the place from which he fled when the scheme collapsed.