Hardin County is a county located in the U.S. State of Tennessee. As of the 2010 census, the population was 26,026. The seat is Savannah. The county was founded in November 1819 and named posthumously for Col. Joseph Hardin, a Revolutionary War soldier and a legislative representative for the Province of North Carolina; the State of Franklin; and the Southwest Territory.Hardin County was the site of the Battle of Shiloh (also known as the Battle of Pittsburg Landing) during the Civil War.