Contrary to common belief, Benedict Arnold contributed more towards the American cause than he detracted. Benedict Arnold was a celebrated General in the Revolutionary War, until his infamous mishap in 1780, which scarred his reputation as an American hero.
Arnold lived from 1741 to 1801. He was born in Norwich, Connecticut, and later on, established a book and drug store in New Haven, Connecticut in 1762. His business made him very wealthy. In 1767 he married Margaret Mansfield, who died in 1775.
Benedict Arnold joined the American army in 1774 as a captain in the Connecticut militia. After the start of the Revolutionary War, he became a colonel in the army and led an attack against Fort Ticonderoga with Ethan Allen in May of 1775.
Later on, in September of 1775, Arnold led 1,150 men into Canada, towards Quebec, and suffered heavy losses on the trip, and was left with only 650 men.
He met with General Richard Montgomery, who had just captured Montreal, and had 300 men. In the battle against Quebec, 100 men were killed, 400 captured, and many wounded, including Arnold, who suffered severe wounds to his leg.
Because of his bravery at Quebec, Arnold was promoted to brigadier general. For the following five years he fought in various battles including the Battle of Valcour, a battle on Lake Champlain.
There are many possible reasons why Benedict Arnold betrayed America. In February of 1777, he was denied a promotion to a major general, and had seniority over the officers that were promoted. This discouraged Arnold to the point that he almost quit the army, and would have, if it had not been for George Washington talking him out of it. Later that year, however, he was promoted as an award for helping against a British raiding party.