John Andre was born in London in 1750 to French Huguenot parents. Well-educated, charming and charismatic, he joined the British army in 1771 and was sent to Germany for specialized training. In 1774 Lt. Andre was sent to Canada, where he was captured and sent to Pennsylvania where he remained until he was exchanged at the end of 1776. He was promoted to Captain and was in Philadelphia during the British occupation. While he was there, he lived in Benjamin Franklin's home and met young Peggy Shippen, who was to become the second wife of Benedict Arnold. In November 1778, he was promoted to Major.
In May 1779, Gen. Benedict Arnold, then commander of West Point, offered to surrender the fort to the English for a fee, using Andre as a negotiator. Despite initial failure in the negotiations, talks resumed with the result that, on the night of 21 Sep 1780, Andre met with Arnold. Upon his return to his ship, Andre found that it had left without him, neccesitating an overland trek through American-held territory. The Brit donned an American uniform, and was captured by three Americans wearing British uniforms.
When Arnold heard that Andre had been arrrested, he fled. Andre was imprisoned at Tappan, NY, where he was found guilty of being behind enemy lines "under a feigned name and in a disguised habit".
His charm endeared him to almost everyone he came into contact with, and one of them was the surgeon James Thacher who wrote his eyewitness account of the hanging on 2 Oct 1780.
Footnote has many images of letters relating to the affair, written by Andre, Washington and Arnold. You can see some of them by clicking on the images to the right. You can also see a record showing James Thacher, surgeon.