The pivotal moment in American Revolutionary War when Benedict Arnold's plot to surrender West Point to British forces was uncovered through the capture of Major John André carrying secret documents.

Benedict Arnold's name has become synonymous with betrayal in American history. His treasonous plot against the Continental Army was discovered on September 23, 1780, when American forces captured British Major John André carrying secret documents. This pivotal moment revealed one of the most shocking betrayal plots of the American Revolution.

The discovery unfolded at a critical point in the war when Arnold, then commander of West Point, had been secretly negotiating with British forces to surrender this crucial American stronghold. What makes this revelation even more dramatic is that Arnold had previously served as one of General George Washington's most trusted and skilled military commanders. His attempted betrayal sent shockwaves through the newly formed nation and forever changed how Americans would view loyalty and patriotism.

Benedict Arnold established himself as one of the Continental Army's most capable commanders before his eventual betrayal. His military accomplishments from 1775-1777 earned him widespread recognition among American forces.

Arnold joined the Connecticut militia in 1774 as a captain of the Governor's Second Company of Guards. He mobilized 60 militiamen in April 1775 following the Battles of Lexington and Concord, leading them on an 8-day march to Cambridge, Massachusetts. His early command experience demonstrated tactical skills in:

• Organizing rapid troop movements across challenging terrain
• Maintaining strict discipline among volunteer soldiers
• Executing precise military maneuvers with limited resources
• Developing effective reconnaissance strategies

Arnold's capture of Fort Ticonderoga in May 1775 marked his first major military success. Working alongside Ethan Allen's Green Mountain Boys, Arnold:

• Led 83 men in a surprise attack on the British garrison
• Secured 78 British cannons without losing a single soldier
• Captured vital military supplies including:

Captured Resources	Quantity
Cannons	78
Mortars	6
Muskets	100
Gunpowder barrels	30

The seized artillery proved crucial for the Continental Army's defense of Boston, establishing Arnold's reputation for bold tactical operations. His command at Ticonderoga earned him promotion to colonel in the Continental Army ranks.

Benedict Arnold's path to treason crystallized in 1780 when his mounting frustrations with the Continental Congress intersected with British intelligence operations. His disillusionment created an opening for British forces to exploit his vulnerabilities.

Major John André served as head of British Intelligence under General Henry Clinton in New York. The initial contact between Arnold and André occurred in May 1779 through Arnold's wife, Peggy Shippen, who'd previously socialized with André during the British occupation of Philadelphia. André's charm combined with his intelligence-gathering expertise made him the ideal handler for this high-level operation.

The clandestine correspondence between Arnold and André started in May 1780 using encrypted messages, codes, and invisible ink. Their letters, signed with the aliases "Gustavus" and "John Anderson," discussed:

• Military information about American troop movements
• Tactical details of West Point's defenses
• Proposed plans for surrendering the fort
• Financial arrangements totaling £20,000 for Arnold's cooperation

Communication Details	Specifics
Start Date	May 1780
Code Names Used	Gustavus (Arnold), John Anderson (André)
Payment Offered	£20,000
Primary Method	Encrypted letters
Key Intermediary	Peggy Shippen Arnold

The secret messages traveled through a network of loyalist merchants between New York City and West Point. Arnold embedded sensitive military intelligence within seemingly innocent business correspondence to avoid detection by American intelligence operations.

The unraveling of Benedict Arnold's treasonous plot began on September 23, 1780, when three American militiamen intercepted British Major John André near Tarrytown, New York.

Three American militiamen—John Paulding, Isaac Van Wart David Williams—spotted André traveling alone on horseback near Tarrytown. André, wearing civilian clothes, carried a pass under the name "John Anderson" signed by Arnold. The militiamen's suspicions grew when André offered increasing amounts of money for his release, reaching 100 guineas plus his horse. Their refusal to accept bribes led to a thorough search of André's person, revealing crucial evidence of Arnold's conspiracy.

The militiamen found six papers hidden in André's boots containing detailed information about West Point's defenses including:

Document Contents	Military Significance
Troop positions	Strategic deployment data
Artillery placements	Defense weak points
Supply inventories	Resource vulnerabilities
Guard schedules	Security patterns

The documents included handwritten notes from Arnold describing how to capture the fort with minimal resistance. Lieutenant Colonel Jameson at North Castle received these papers recognized Arnold's handwriting. Jameson sent the documents to General Washington while dispatching a messenger to alert Arnold about André's capture—an action that inadvertently gave Arnold time to escape to British-controlled New York.

Benedict Arnold's treason reached its climax on September 25, 1780, when he fled to British-controlled territory upon learning of André's capture. His escape marked a defining moment in American military history that reshaped the course of the Revolutionary War.

Arnold learned of André's capture through Lieutenant Colonel Jameson's message at 8:00 AM while at his West Point headquarters. He immediately mounted his horse and fled down the Hudson River to the British sloop-of-war Vulture. Arnold left behind his wife Peggy Shippen Arnold who feigned hysteria when questioned by George Washington's officers. The British awarded Arnold £6,315 plus an annual pension of £360 for his defection despite the plot's failure.

The discovery of Arnold's treason strengthened American resolve in three significant ways:

• Unified the Continental Army by eliminating internal dissent

• Enhanced security protocols for military communications

• Reinforced West Point's defensive positions with additional troops

• Lost valuable intelligence about American troop movements

• Failed to secure West Point's strategic position

• Damaged relationships with American loyalists who viewed Arnold's actions as dishonorable

Military Impact Statistics	Before Arnold's Treason	After Arnold's Treason
West Point Garrison Size	3,000 troops	4,500 troops
British Intelligence Sources	12 active contacts	3 active contacts
Monthly Desertion Rate	8.5%	2.3%
Fort Defense Budget	$25,000	$42,000

Benedict Arnold's post-treason life unfolded in two distinct phases: his military service with the British forces and his later exile in England. His defection earned him £6,315 plus an annual pension of £360 from the British government.

Arnold received a commission as brigadier general in the British Army in 1780. He led British forces on raids in Virginia during 1781, burning Richmond, Petersburg, and several other towns. In September 1781, Arnold commanded a force of British troops in a raid on New London, Connecticut, destroying 143 buildings and capturing Fort Griswold.

Arnold's British Military Campaigns	Impact
Richmond Raid (January 1781)	27 buildings destroyed
Petersburg Campaign (April 1781)	4 tobacco warehouses burned
New London Raid (September 1781)	143 buildings destroyed, 85 casualties

Arnold relocated to London in December 1781, where he established a merchant trading business. His attempts to secure additional military commands from the British government proved unsuccessful. Arnold moved to Saint John, New Brunswick in 1785, operating a West Indies trading company until declaring bankruptcy in 1791. He returned to London in 1792, died on June 14, 1801, and was buried at St. Mary's Church, Battersea.

Location	Years	Primary Activities
London	1781-1785	Merchant trading
Saint John	1785-1791	West Indies trade
London	1792-1801	Various business ventures

• Benedict Arnold's treason was discovered on September 23, 1780, when American militiamen captured British Major John André carrying secret documents about West Point's defenses.
• Prior to his betrayal, Arnold was one of the Continental Army's most capable commanders, known for capturing Fort Ticonderoga and leading successful military campaigns from 1775-1777.
• The treasonous plot involved secret communications between Arnold and Major André using coded messages and aliases, with Arnold agreeing to surrender West Point for £20,000.
• After André's capture revealed the conspiracy, Arnold escaped to British-controlled territory on September 25, 1780, where he received a brigadier general commission in the British Army.
• The discovery of Arnold's treason actually strengthened the Continental Army by improving security protocols and increasing troop numbers at West Point.

Benedict Arnold's treason stands as one of the most significant betrayals in American military history. His plot's discovery on September 23 1780 transformed him from a celebrated war hero into America's most notorious traitor. While the immediate impact threatened West Point's security it ultimately led to stronger military protocols and a more unified Continental Army.

Today Arnold's name remains a powerful symbol of betrayal in American culture. His story serves as a reminder that loyalty and patriotism aren't guaranteed by past achievements but must be continuously upheld through unwavering dedication to one's principles and nation.