The county was established on December 14, 1798. At that time, it became the 31st county to be established in Kentucky. It was derived from parts of Franklin and Shelby counties. Later, parts of the county were pared off to create three additional counties: Owen in 1819, Trimble in 1836, and Carroll in 1838. Today Gallatin is only one-tenth of its original size and its’ most northern border is the Ohio River. Sitting at only 105 square miles, it is home to 8,832 residents.