The Philadelphia skyline from the South Street Bridge, January 2020
Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Since 1854, the city has been coextensive with Philadelphia County, the most populous county in Pennsylvania and the urban core of the Delaware Valley, the nation's seventh-largest and one of world's largest metropolitan regions, with 6.245 million residents . The city's population as of the 2020 census was 1,603,797, and over 56 million people live within 250 mi (400 km) of Philadelphia.
With 18 four-year universities and colleges, Philadelphia is one of the nation's leading centers for higher education and academic research. , the Philadelphia metropolitan area was the nation's ninth-largest metropolitan economy with a gross metropolitan product (GMP) of US$479 billion. Philadelphia is the largest center of economic activity in Pennsylvania and the broader multi-state Delaware Valley region; the city is home to five Fortune 500 corporate headquarters as of 2022. The Philadelphia skyline, which includes several globally renowned commercial skyscrapers, is expanding, primarily with new residential high-rise condominiums. The city and the Delaware Valley are a biotechnology and venture capital hub; and the Philadelphia Stock Exchange, owned by NASDAQ, is the nation's oldest stock exchange and a global leader in options trading. 30th Street Station, the city's primary rail station, is the third-busiest Amtrak hub in the nation, and the city's multimodal transport and logistics infrastructure, including Philadelphia International Airport, the PhilaPort seaport, freight rail infrastructure, roadway traffic capacity, and warehouse storage space, are all expanding. (Full article...)