Dauphin County, PA
Dauphin County/dfn/ is a county in the U.S. state of Pennsylvania. As of the 2010 census, the population was 268,100. The county seat and the County's largest city is Harrisburg,Pennsylvania's state/commonwealth capital and tenth largest city. The county was created/"erected" on March 4, 1785, from part of Lancaster County and was named after Louis-Joseph, Dauphin of France the first son of Louis XVI. Dauphin County is included in the HarrisburgCarlisle, PA Metropolitan Statistical Area. Located within the county is Three Mile Island Nuclear Generating Station, site of the 1979 nuclear core meltdown.