Center City includes the central business district and central neighborhoods of Philadelphia, in the U.S. state of Pennsylvania. It is the former City of Philadelphia prior to the Act of Consolidation, 1854 which extended the city borders to be coterminous with Philadelphia County. Center City has grown into the second-most populated downtown area in the United States, after Midtown Manhattan in New York City, with an estimated 183,240 residents in 2015.