He died as prisoner of war and is buried at Danville Virginia National Cemetery. So this is his memorial cenotaph.
Death date reported varies somewhat, with wife's death date and his apparently on the same date, according to one source. With earlier date listed on Vt in the Civil War website and reported in The Rutland County Herald..
His service record courtesy of Vermont In The Civil War website: MILITARY SERVICE
Age: 44, credited to Northfield, VT
Unit(s): 11th VT INF, 12th VT INF
Service: enlisted 8/23/62, mustered in 10/4/62, Pvt, Co. F, 12th VT INF, discharged / disability 2/18/63; enlIs Ted 11/14/63, mustered In 12/1/63, POW / Prisoner Of War Weldon Railroad, 6/23/64, Danville, dIED in prison 9/20/64
A Civil War Veteran: PVT, Co. F, 12th VVI (Vt Vol Infantry)