Thaddeus Leavitt (September 9, 1750 – 1813) was an American merchant who invented an improved upon version of the cotton gin,[1] as well as joining with seven other Connecticut men to purchase most of the three-million-plus acres of the Western Reserve lands in Ohio from the government of Connecticut, land on which some of his family eventually settled, founding Leavittsburg, Ohio, and settling in Trumbull County, Ohio. Leavitt served on a commission in the early nineteenth century to settle boundary disputes between Massachusetts and Connecticut, was a director of one of Connecticut's first banks, and was a shipowner whose vessels traded throughout the Atlantic. Leavitt also kept a journal in which he noted everything from the weather to 'cures' for various ailments to the adoption of the United States Constitution.