 In September, 1864, he was elected as a member of the Vermont House, which was in session on October 19, 1864, when the St. Albans raid occurred.Barstow was sent to the scene, later went to Canada on a special mission, and subsequently commanded as a brigadier general one of the militia brigades raised in response.He commanded troops on the northwestern border of the state until relieved by George J. Stannard in January 1865.