 It is named for Alexander Hamilton, Revolutionary War hero and the first United States Secretary of the Treasury.On March 18, 1925, the infamous Tri-State Tornado tore across the county, destroying dozens of homes and farms in Flannigan, Twigg, Mayberry and Crook townships, and killing 37 people.According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.3%) is water.