He removed to Norway, New York and engaged in mercantile pursuits.
He was a presidential elector in 1816 and voted for James Monroe and Daniel D. Tompkins.
Fosdick was elected as an Adams man to the 19th United States Congress, holding office from March 4, 1825, to March 3, 1827.
He was Collector of Customs at the Port of New London from 1849 to 1853.
He was buried at the Cedar Grove Cemetery in New London.