He engaged in lumbering on the Delaware River and in mercantile pursuits and banking at Port Jervis, New York.

He served as internal revenue collector and later as president of the Barrett Bridge Co.. St. John was elected as a Republican to the Forty-second and Forty-third Congresses (March 4, 1871 – March 3, 1875), after which he resumed his former business activities.

He died in Port Jervis on July 6, 1891, and was interred in Laurel Grove Cemetery.

The Inn would form the basis for the home of Anthony R. Kuser who converted it into a lodge before ultimately donating it to New Jersey in 1923.

[1] This article incorporates public domain material from the Biographical Directory of the United States Congress