The seat of Cuyahoga County, Cleveland is Ohio's second largest city and is at the center of a metropolitan statistical area that encompasses Cuyahoga, Geauga, Lake, and Medina counties. The city's location on Lake Erie accounts for its success as a transportation, industrial, and commercial center. Cleveland contributed a number of industrial discoveries that benefited national growth and prosperity in the nineteenth century. In the early twentieth century, the local political system set a standard for reform that contributed to the general welfare of its citizens. Today Cleveland's revitalized central business and commercial districts complement its cultural institutions and major professional sports teams.