At the outbreak of the War of Independence he abandoned the study of medicine to enter the American army, and he served with General Benedict Arnold in the Quebec campaign and was later under General Horatio Gates, acting from May 1777 to March 1778 as adjutant-general of the Northern Department.
Fort Ticonderoga, the key to the passage of Lakes George and Champlain to Canada, was surprised and, taken on the 10th of May by a small band under Colonel Ethan Allen, while Colonel Benedict Arnold headed an expedition through the Maine woods to effect the capture of Quebec, where Sir Guy Carleton commanded.
There he found British v detachments, 2000 strong, composed of troops whom Clinton had sent down separately under Generals Benedict Arnold and William Phillips to establish a base in the Chesapeake, as a diversion in favour of the operations of Cornwallis in the Carolinas.
On the 19th Burgoyne attacked the American left under General Benedict Arnold.
In January 1781 Benedict Arnold captured Richmond and compelled governor and legislature to flee beyond the Blue Ridge mountains, where one session of the Assembly was held.
