 He was ordained to the priesthood on August 22, 1920, by Bishop Edmund Gibbons.In 1938 Father Grassmann founded the Fonda Memorial of Catherine Tekakwitha near Fonda, New York.This was in the vicinity of the Mohawk settlement Caughnawaga, where Catholic convert Kateri Tekakwitha had lived part of her life (1656-1680) and been baptized.