 Although Fleming had reservations about the new U.S. Constitution, he voted in favor of ratification as his constituents had instructed.He also served on the board of trustees of Washington College (later Washington and Lee University), and was known for having one of the finest libraries in the western part of the Commonwealth.Fleming's health visibly declined by 1792, and he was unable to visit his Warfield grandchildren in Kentucky, but he still managed to visit New London in September, as well as arrange for the marriage of his daughter Eliza to Cary Allen in 1794.