sentences:  In 1799, he wrote to then Maj. Gen. Alexander Hamilton, recommending Mr. Joseph Hickcox to fill in the vacancy in the 13th Regiment of the Army of the United States caused by the vacancy in the line due to James Gordon's new role as Office of the Quarter Master.He was a member of the New York State Assembly from 1810 to 1812, and was District Attorney of the Third District (comprising Columbia, Greene and Rensselaer counties) from 1810 to 1811.Grosvenor was elected as a Federalist to the 12th United States Congress to fill the vacancy caused by the resignation of Robert Le Roy Livingston, and was re-elected to the 13th and 14th United States Congresses, serving from January 29, 1813, to March 4, 1817.