Benedict was born in Norwich, Connecticut in 1741. He was an apprentice druggist until he quit to fight in the French Indian War. Benedict then served in the New York militia until he became a deserter a year later. A short time later he returned to Norwich to complete his druggist apprenticeship. When Benedict was just 21 years of age his parents died, leaving him a large sum of money. At the time he and his sister moved to New Haven, Connecticut, and they opened up a pharmacy and bookstore. The business soon profited, and before long Benedict owned several trading ships which sailed as far as the West Indies.
Benedict married Margaret Mansfield in 1775, and was eager to fight the British who he felt had an economically oppressive hold on the colonies. Once more he enlisted, only this time as the leader of the Connecticut militia. Before long, Benedict Arnold marched his troops into Canada, attacking Quebec, in what became a disastrous defeat. However, it didn't seem to matter because on his return home Benedict was promoted first to brigadier general, and then just a short time later he was promoted to major general.
Next, after the British had withdrawn, Benedict Arnold was placed in charge of the Philadelphia garrison. In Philadelphia, Benedict learned about the good life, and he began socializing with the most prosperous people in the city who were all Tories or British Loyalists. Before long, General Benedict Arnold and his new wife were deeply in debt, and visibly living beyond his means. Then, his whole world came tumbling down when in February of 1779, he was charged with using government funds to finance his personal life. However, Congress did not want to smear a war hero, and as a result he was not punished.
His wife would die after just 5 years of marriage, leaving Benedict 3 sons. He would soon marry 19 year old Peggy Shippen, who was from one of Philadelphia's most prominent Tory families. Now he was spending more money than ever before, and both the civilian and military authorities began asking questions. Finally, he became completely desperate and contacted an aid of the British General Clinton, named Major John Andre. In a message, General Benedict Arnold told them that he would help the British anyway that he could if they would give him 20,000 British pounds. He wanted 10,000 pounds up front. Benedict Arnold told General Clinton that he was next in line for the command of West Point and he could arrange for its surrender, He was very serious about getting the money first, and he proceeded to use his wife as a courier. She gave Major Andre tidbits of secret information about impending battle plans.
Major Andre and Benedict Arnold decided to meet in the woods near the Hudson River to finalize their plans. They decided to used Joshua Hett Smith as their messenger. Major Andre arrived on a boat called the “Vulture.” The three plotted the takeover until 4 o'clock in the morning. Then they went to spend the night at Smith's house. The next morning the Vulture came under attack and was rendered useless. Arnold didn't want to lose his money so he told Smith and Andre that they should put their plans in Andre's boots and walk back to the British lines. General Arnold wrote them passes, which he told them would get them through enemy lines, instead they aroused suspicion. Then before General Washington could be alerted, Benedict Arnold fled and was quickly recruited by the British. Major Andre was executed by George Washington himself.