Adams County Courthouse Seal Location within the U.S. state of Ohio Ohio's location within the U.S. Coordinates: 3850N8329W / 38.84N 83.48W / 38.84; Country United States State Ohio Founded July 10, 1797[1] Named for John Adams Seat West Union Largest village West Union Area Total 586 sq mi (1,520 km2) Land 584 sq mi (1,510 km2)