Benedict Arnold commits treason

On September 21, 1780, Benedict Arnold gave British Major John André plans to West Point. From the article:

"Benedict Arnold commits treason
On September 21, 1780, during the American Revolution, American General Benedict Arnold meets with British Major John Andre to discuss handing over West Point to the British, in return for the promise of a large sum of money and a high position in the British army. The plot was foiled and Arnold, a former American hero, became synonymous with the word “traitor.”

Arnold was born into a well-respected family in Norwich, Connecticut, on January 14, 1741. He apprenticed with an apothecary and was a member of the militia during the French and Indian War (1754-1763). He later became a successful trader and joined the Continental Army when the Revolutionary War broke out between Great Britain and its 13 American colonies in 1775. When the war ended in 1783, the colonies had won their independence from Britain and formed a new nation, the United States.

During the war, Benedict Arnold proved himself a brave and skillful leader, helping Ethan Allen’s troops capture Fort Ticonderoga in 1775 and then participating in the unsuccessful attack on British Quebec later that year, which earned him a promotion to brigadier general. Arnold distinguished himself in campaigns at Lake Champlain, Ridgefield and Saratoga, and gained the support of George Washington. However, Arnold had enemies within the military and in 1777, five men of lesser rank were promoted over him. Over the course of the next few years, Arnold married for a second time and he and his new wife lived a lavish lifestyle in Philadelphia, accumulating substantial debt. The debt and the resentment Arnold felt over not being promoted faster were motivating factors in his choice to become a turncoat.

In 1780, Arnold was given command of West Point, an American fort on the Hudson River in New York (and future home of the U.S. military academy, established in 1802). Arnold contacted Sir Henry Clinton, head of the British forces, and proposed handing over West Point and his men. On September 21 of that year, Arnold met with Major John Andre and made his traitorous pact. However, the conspiracy was uncovered and Andre was captured and executed. Arnold, the former American patriot, fled to the enemy side and went on to lead British troops in Virginia and Connecticut. He later moved to England, though he never received all of what he’d been promised by the British. He died in London on June 14, 1801."