Benedict Arnold's Treason
America's most successful general plots to hand West Point to the British
Quick facts
- Location
- West Point, New York
- Date
- 25 September 1780 (Arnold's escape)
- Co-conspirator
- Major John Andre, British Army, captured and hanged as a spy
- Outcome
- Arnold escapes to British lines; commands British troops thereafter
What happened
Benedict Arnold, celebrated for his battlefield courage at Saratoga but embittered over debts, passed-over promotions, and a court-martial reprimand, took command of the strategic Hudson River fortress at West Point on 3 August 1780. He then secretly negotiated with British Major John Andre to surrender the fort's defenses in exchange for money and a British commission. The plot unraveled when New York militiamen captured Andre carrying incriminating papers on 23 September 1780; Arnold learned of the arrest just in time to escape down the Hudson to a waiting British ship on 25 September, narrowly avoiding Washington, who arrived at West Point shortly after and discovered the betrayal. Andre was tried and hanged as a spy; Arnold went on to fight for the British.
Why it matters
Had the plot succeeded, the British would have controlled the Hudson River, potentially splitting New England from the other states and dealing a severe blow to the American war effort. Arnold's name became, and remains, synonymous with treason in American memory, a stark contrast to his earlier record as one of the war's most effective battlefield commanders.
How we know
American Battlefield Trust holds a contemporary letter from Edmund Pendleton describing Arnold's corruption as it became known, alongside its biographical account of Arnold's command at West Point and Andre's capture.
Sources
- American Battlefield Trust. Benedict Arnold · Reputable sourcebattlefields.org · The domain "battlefields.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- American Battlefield Trust (primary source: Edmund Pendleton letter). Benedict Arnold's Treason · Primary source (author-declared)battlefields.org · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
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