Ohio: Hamilton County

Hamilton County, Ohio, was established on January 2, 1790. It was the second county formed in the Northwest Territory. Residents named the county in honor of Alexander Hamilton, who was the first Secretary of the Treasury of the United States and a founder of the Federalist Party. The county consists of 407.4 square miles, with an average of 2,075 residents per square mile in 2000. Located in the southwestern corner of Ohio, the county's southern border helps form Ohio's boundary with Kentucky, while its western border helps form the state's boundary with Indiana. Cincinnati is the county's largest city and the county seat.