 He was Judge of Common Pleas in New York from 1818 to 1820, and was first judge of Westchester County from 1820 to 1842, when he was removed on account of his anti-slavery views.An enthusiastic member of the American Anti-Slavery Society, whose constitution he drafted,
Jay stood with James Birney at the head of the conservative abolitionists, and by his calm, logical, and judicial writings exerted for many years a powerful influence.From 1835 to 1837 he was the society's corresponding foreign secretary.