He represented the City of St. John in the Legislative Assembly of New Brunswick from 1876 to 1882 as a Liberal member.
He was born in Pictou County, Nova Scotia, the son of Alexander McNaughton Marshall, of Scottish descent.
He was a commissioner for the General Public Hospital at Saint John and a lieutenant in the local militia.
Marshall was also a prominent member in the local Masonic lodge and a Grand Master for the province.
He ran unsuccessfully for a seat in the provincial assembly in 1874 but was elected in an 1876 by-election held after the death of William H.A.