Benedict Arnold (1741 - 1801) was a Major General of the Continental Army during the American Revolutionary War. From 1775 to 1780, Arnold both took part in prominent battles like that of Saratoga or led campaigns himself, notably an invasion of Quebec. Despite a good working relationship with his immediate superior George Washington, Arnold had few useful political allies and an increasing number of opponents in the Continental Congress. He was consistently passed over for promotion while his finances were diminishing.
From 1778 to 1779, Arnold was offered the military command of Philadelphia. In 1779, he married Peggy Shippen, a member of the Loyalists who brought him into contact with Henry Clinton, the British Commander-in-Chief of North America. Since July, 1779, Arnold started passing to the British information on American troop locations and strengths, as well as the locations of supply depots. He was actively negotiating terms for a possible defection to their side.
In 1780, Arnold was transferred to West Point, New York. His new position "gave him authority over the entire American-controlled Hudson River, from Albany down to the British lines outside New York City". Arnold started working on a plan to surrender the area to the British and thus secure himself a good position in their Army. The plot failed due to a security breach in the passing of information. Arnold fled to the British lines. George Washington secured safe passage for Peggy to go join her husband.
While Arnold had failed, the British still offered him a position as Brigadier General. He continued leading campaigns, including successful raids of his native Connecticut. He has been called "the best general on either side of the conflict", though some of his victories were Pyrrhic ones. That it cost more British casualties than could be afforded. The end of the War in 1781 found him moving from New York to London. His pay was reduced as was that of all British officers serving at times of peace. He campaigned to start a new war against the Americans but found himself on the minority side on the matter. In fact political opponents targeted him as a "mean mercenary" who would adopt any cause "for the sake of plunder".
In 1785, Arnold moved to New Brunswick, Canada with his family and started a new career as a trader. His trade with the West Indies could prove profitable but Arnold made a number of bad business deals and was involved in several petty lawsuits. His popularity was at an all-times-low when the Arnolds moved back to London in 1791. In 1792, Arnold had a bloodless duel with James Maitland, 8th Earl of Lauderdale, a prominent politician who had insulted him.
The French Revolutionary Wars offered him a new opportunity for action. He continued his trading business but also outfitted his own privateer and helped organize militia forces in the British islands of the Caribbean. He was rewarded with a large land grant in Upper Canada. He kept the land but continued living in London. He died of dropsy in 1801. He was survived by seven legitimate sons, one legitimate daughter and at least one illegitimate son. Several of his sons would follow military careers of their own. His legacy is controversial. He showed undeniable heroism on the battlefield while fighting on both sides of the war, though the Battle of Saratoga was arguably his best moment. But the question of his actual loyalties and motivations remains. By the 19th century, his name became synonymous with "defector" and "traitor" in the United States, but the assessment has been contested repeatedly.