William Rockwell was born in Sharon, Connecticut, on September 20, 1803. He graduated Yale College with the class of 1822, commenced his legal studies and was admitted to the bar in the State of Connecticut in 1825. Rockwell practiced law in Sharon, Connecticut, from 1824 to 1827, and then moved to Brooklyn, New York, where he set up a law office.
During the years 1833 to 1839, he served as District Attorney of Kings County. In June, 1847, he was reported to have been elected Judge of the Kings County Court, but the election was contested and his opponent was seated. In November, 1853, he was elected Judge of the New York State Supreme Court and held office until his sudden death from yellow fever on July 26, 1856.
William Rockwell is remembered most for his judgment in the landmark street-car desegregation case, Jennings v. Third Ave. Railroad Co.
Franklin Bowditch Dexter. Biographical Notices of Graduates of Yale College (1913).
Dwight Canfield Kilbourn. The Bench and Bar of Litchfield County, Connecticut, 1709-1909 (1909).