John Duer entered the army at age 16, but after two years left for the study of law. He was trained in the office of Alexander Hamilton, began a practice in Orange County, New York, and moved to New York City in 1820, where he was a highly successful insurance lawyer.
He was a delegate to the State constitutional convention in 1821. In 1825 he was appointed one of the commissioners to revise the state statutes, and was especially active in preparing the first half of the work. From 1828 to 1829 he was United States Attorney for the Southern District of New York.
He was elected an associate judge of the New York Superior Court in 1849, and on the death of Judge Thomas J. Oakley in 1857, Duer became Chief Justice.
At the time of his death, he was editing Duer's Reports of the Decisions of the Superior Court, the sixth volume of which he left incomplete.
His other published works include:
- A Lecture on the Law of Representations in Marine Insurance, with Notes and Illustrations (New York, 1844)
- A Treatise on the Law and Practice of Marine Insurance, which became a standard authority in the United States (2 vols., 1845–46)
- A Discourse on the Life, Character, and Public Services of James Kent, Chancellor of the State of New York, delivered by request before the judiciary and bar of the city and county of New York (12 April 1848)
- Three of the Revised Statutes of the State, in connection with Benjamin F. Butler and John C. Spencer
|This article does not cite any references or sources. (April 2013)|
- This article incorporates text from a publication now in the public domain: Wilson, James Grant; Fiske, John, eds. (1900). "Duer, William". Appletons' Cyclopædia of American Biography. New York: D. Appleton.
- John Duer at Find a Grave
- Sketches of Some of the Prominent Members of the Orange County Bar, by Walter Case Anthony (1917)
Robert L. Tillotson
|U.S. Attorney for the Southern District of New York
1828 - 1829
James A. Hamilton