In 1804, Fay removed to Northampton, then in Montgomery County. He became a land surveyor and later engaged in agricultural pursuits, milling, and manufacturing. He held various local offices and was Postmaster of Northampton for several years. He was a member from Montgomery County of the New York State Assembly in 1808-09 and 1812.
Fay was elected as a Democratic-Republican to the 16th United States Congress, holding office from March 4, 1819, to March 3, 1821. Afterwards he resumed his former activities. He was a presidential elector on the Democratic James K. Polk ticket in 1844.
He was buried at the Old Presbyterian Church Cemetery in Northampton.
- United States Congress. "John Fay (id: F000052)". Biographical Directory of the United States Congress.
- The New York Civil List compiled by Franklin Benjamin Hough (pages 70, 182, 186, 273, 322, 330; Weed, Parsons and Co., 1858)
|U.S. House of Representatives|
|Preceded by |
| Member of the U.S. House of Representatives |
from New York's 14th congressional district