Benedict Arnold (January 14, 1741 – June 14, 1801) was a general in the Continental Army during the American Revolutionary War. He is best known for betraying the United States forces and plotting to surrender the American fort at West Point, New York, to the British during the American Revolution.

Arnold had distinguished himself as a hero of the revolution early in the war through acts of cunning and bravery at Fort Ticonderoga in 1775, the march to Canada, attack on Montreal and besieging of Quebec in 1775, the Battle of Valcour Island on Lake Champlain in 1776, the Battles of Danbury and Ridgefield in Connecticut (after which he was promoted to Major General) and at the Battle of Saratoga in 1777. However, Arnold strongly opposed the decision by the Continental Congress to form an alliance with France. Disaffected because of grievances with the Continental Congress (despite his seniority and accomplishments, Congress had passed Arnold over for promotion), suffering from mounting personal debt (he had personally paid for nearly all of the expenditures of his Continental forces while in Canada), and facing corruption charges filed by the Pennsylvania civil authorities (at the instigation of a man Arnold had stripped of command at Ticonderoga), Arnold also faced pressure at home from his young second wife Peggy Shippen, herself a British Loyalist.

In September 1780, he formulated his scheme, which, if successful, would have given British forces control of the Hudson River valley and split the colonies in half. The plot was thwarted, but Arnold managed to flee to British forces in New York with the help of John Borns, where he was rewarded with a commission as a Brigadier General in the British Army, along with a reduced reward of £6,000.

Arnold was born the sixth of six children to Arnold III and Hannah Waterman King in Norwich, Connecticut in 1741. He was named after his great-grandfather Benedict Arnold, an early colonial governor of the Colony of Rhode Island and Benedict IV, who died in infancy before Benedict Arnold V was born. Only Benedict and his sister Hannah survived to adulthood; the other three siblings succumbed to yellow fever while children. Through his maternal grandmother, Arnold was a descendant of John Lathrop, an ancestor of at least four Presidents of the United States.

The Arnold family was financially well off until Arnold's father made several bad business deals that plunged the family into debt. When this happened, the father turned to alcohol for solace. At 14, Benedict was forced to withdraw from school because the family no longer could afford the cost.

His father's alcohol abuse and ill health prevented him from training his son in the family mercantile business, but his mother's family connections secured an apprenticeship for him with two of her cousins, the brothers Daniel and Joshua Lathrop. The two ran a successful apothecary and general merchandise trade in Norwich.

At 15, Arnold enlisted in the Connecticut militia, marching to Albany and Lake George to oppose the French invasion from Canada at the Battle of Fort William Henry. In any case, the British suffered a humiliating defeat at the hands of the French under the command of Louis Joseph Marquis de Montcalm. Subsequent to the British surrender, the native friends of the French were outraged by the easy terms offered to the British and Colonial forces. They had been promised scalps, arms and booty, and none was forthcoming. They fell upon the prisoners as they were being escorted away and massacred as many as 180 of them. The French regulars were powerless to stop them. ^[1]. This event may have created an abiding hatred for the French in a young and impressionable Arnold that influenced his actions later in life.

Benedict's mother, to whom he was very close, died in 1759. The youth took on the responsibility of supporting his ailing father and younger sister. His father's alcoholism worsened after the death of his wife; he was arrested on several occasions for public drunkenness and also was refused communion by his church. With his father's death in 1761, the 20-year-old Arnold resolved to restore his family name to the elevated status it had once enjoyed. until his treason later in life

In 1762, with the help of the Lathrops, Arnold established himself in business as a pharmacist and bookseller in New Haven, Connecticut.

Arnold was ambitious and aggressive, quickly expanding his business. In 1763, he repurchased the family homestead that his father had sold when deeply in debt. One year later, he re-sold it for a substantial profit. In 1764, he formed a partnership with Adam Babcock, another young New Haven merchant. Using the profits from the sale of his homestead, they bought three trading ships and established a lucrative West Indies trade. During this time, he brought his sister Hannah to New Haven and established her in his apothecary to manage the business in his absence. He traveled extensively in the course of his business, throughout New England and from Quebec to the West Indies, often in command of one of his own ships.

The Stamp Act of 1765 severely curtailed mercantile trade in the colonies. Arnold initially took no part in any public demonstrations but, like many merchants, conducted trade as if the Stamp Act did not exist—in effect becoming a smuggler in defiance of the act.

On the night of January 31, 1767, Arnold took part in a demonstration denouncing the acts of the British Parliament and their oppressive colonial policy. The effigies of local crown officials were burned. He and members of his crew roughed up a man suspected of being a smuggling informant. Arnold was arrested and fined 50 shillings for disturbing the peace.

The oppressive taxes levied by parliament forced many New England merchants out of business. Arnold himself came near to personal ruin, falling £15,000 in debt.

Arnold fought a duel in Honduras with a British sea captain, who called Arnold a "Dammed Yankee, destitute of good manners or those of a gentleman". Arnold was shocked by the rudeness and challenged him to a duel. The captain was wounded and forced to apologize.

Arnold was in the West Indies when the Boston Massacre occurred on March 5, 1770, but later he wrote "very much shocked" and wondered "good God; are the Americans all asleep and tamely giving up their liberties, or are they all turned philosophers, that they don't take immediate vengeance on such miscreants".

On February 22, 1767, he married Margaret, daughter of Samuel Mansfield. They had three sons: Benedict, Richard and Henry. She died on June 19, 1775.

In July 1780, Arnold sought and obtained command of the fort at West Point. He already had begun correspondence with General Sir Henry Clinton in New York City through Major André and was closely involved with Beverley Robinson, a prominent loyalist in command of a loyalist regiment. Arnold offered to hand the fort over to the British for £20,000 and a brigadier's commission. His plans were thwarted when André was captured with a pass signed by Benedict Arnold, and he was in possession of documents that disclosed the plot and incriminated Arnold. André later was denied his request of a soldier's death by a firing squad and instead was convicted of being a spy and hanged.

Arnold learned of André's capture and fled to the British. They made him a brigadier general, but only paid him some £ 6,000 because his plot had failed.

The British never really trusted Arnold, although he saw some action in the American theater. In December, under orders from Clinton, Arnold led a force of 1,600 troops into Virginia and captured Richmond, cutting off the major artery of material to the southern colonial effort. It is said that Arnold asked an officer he had taken captive about what the Americans would do if they captured Arnold, and the captain is said to have replied "Cut off your right leg, bury it with full military honors, and then hang the rest of you on a gibbet." In the Southern Theater, Lord Cornwallis marched north to Yorktown, which he reached in May 1781. Arnold, meanwhile, had been sent north to capture the town of New London, Connecticut, in hopes it would divert Washington away from Cornwallis. While in Connecticut, Arnold's force captured Fort Griswold on September 8. In December, Arnold was recalled to England with various other officers as the Crown de-emphasized the American Theater over others in which victories were more likely.

Benedict Arnold pursued interests in the shipping trade in Canada from 1787 to 1791, before moving to London. He died in 1801 and was buried at St. Mary's Church, Battersea in London, England. He is said to have died poor, in bad health, and essentially unknown.

• Arnold Cipher - A message sent by Arnold to John André
• Boot Monument
• Newport Tower (Rhode Island)

• Barry K. Wilson, 2001, Benedict Arnold: A Traitor in Our Midst, McGill Queens Press. ISBN 077352150X (This book is about Arnold's time in Canada both before and after his treachery)
• James L. Nelson, 2006, Benedict Arnold's Navy: The Ragtag Fleet that Lost the Battle of Lake Champlain but Won the American Revolution, McGraw-Hill. ISBN 0-07-146806-4 (This book shows how Benedict Arnold's leadership against the British forces on Lake Champlain secured for America the independence that he would try later to betray.)

• Biography at the Dictionary of Canadian Biography Online
• Some details from ushistory.org
• Biographical profile of Arnold written in the 1880s
• Another biography - with more ancestry details
• Biographical sketch by a contemporary, reflecting American sentiment towards Arnold
• Benedict Arnold's Portraits
• usahistory site - includes details on Arnold's escape
• Resort located on Arnold's trail to Quebec City