Chicago (Union Station), Illinois

Philadelphia (30th Street Station), Pennsylvania

Chicago ( , locally also ), officially the City of Chicago, is the most populous city in the U.S. state of Illinois and the third most populous city in the United States. With an estimated population of 2,705,994 (2018), it is also the most populous city in the Midwestern United States. Chicago is the county seat of Cook County, the second most populous county in the US, with portions of the northwest city limits extending into DuPage County near O'Hare Airport. Chicago is the principal city of the Chicago metropolitan area, often referred to as Chicagoland. At nearly 10 million people, the metropolitan area is the third most populous in the nation. Located on the shores of freshwater Lake Michigan, Chicago was incorporated as a city in 1837 near a portage between the Great Lakes and the Mississippi River watershed and grew rapidly in the mid-19th century. After the Great Chicago Fire of 1871, which destroyed several square miles and left more than 100,000 homeless, the city made a concerted effort to rebuild. The construction boom accelerated population growth throughout the following decades, and by 1900, less than 30 years after the great fire, Chicago was the fifth-largest city in the world. Chicago made noted contributions to urban planning and zoning standards, including new construction styles (including the Chicago School of architecture), the development of the City Beautiful Movement, and the steel-framed skyscraper.Chicago is an international hub for finance, culture, commerce, industry, education, technology, telecommunications, and transportation. It is the site of the creation of the first standardized futures contracts, issued by the Chicago Board of Trade, which today is the largest and most diverse derivatives market in the world, generating 20% of all volume in commodities and financial futures alone. Depending on the particular year, the city's O'Hare International Airport is routinely ranked as the world's first or second busiest airport according to tracked data by the Airports Council International. The region also has the largest number of federal highways and is the nation's railroad hub. Chicago was listed as an alpha global city by the Globalization and World Cities Research Network, and it ranked seventh in the entire world in the 2017 Global Cities Index. The Chicago area has one of the highest gross domestic products (GDP) in the world, generating $680 billion in 2017. In addition, the city has one of the world's most diversified and balanced economies, with no single industry employing more than 14% of the workforce. Chicago is home to several Fortune 500 companies, including Allstate, Boeing, Exelon, Kraft Heinz, McDonald's, Mondelez International, Sears, United Airlines Holdings, and Walgreens. Chicago's 58 million domestic and international visitors in 2018 made it the second most visited city in the nation, not far behind New York City's 65 million visitors in 2018. The city was ranked first in the 2018 Time Out City Life Index, a global quality of life survey of 15,000 people in 32 cities. Landmarks in the city include Millennium Park, Navy Pier, the Magnificent Mile, the Art Institute of Chicago, Museum Campus, the Willis (Sears) Tower, Grant Park, the Museum of Science and Industry, and Lincoln Park Zoo. Chicago's culture includes the visual arts, literature, film, theatre, comedy (especially improvisational comedy), food, and music, particularly jazz, blues, soul, hip-hop, gospel, and electronic dance music including house music. Of the area's many colleges and universities, the University of Chicago, Northwestern University, and the University of Illinois at Chicago are classified as "highest research" doctoral universities. Chicago has professional sports teams in each of the major professional leagues, including two Major League Baseball teams.

Philadelphia, known colloquially as Philly, is the largest city in the U.S. state and Commonwealth of Pennsylvania, and the sixth-most populous U.S. city, with a 2018 census-estimated population of 1,584,138. Since 1854, the city has had the same geographic boundaries as Philadelphia County, the most populous county in Pennsylvania and the urban core of the eighth-largest U.S. metropolitan statistical area, with over 6 million residents as of 2017. Philadelphia is also the economic and cultural anchor of the greater Delaware Valley, located along the lower Delaware and Schuylkill Rivers, within the Northeast megalopolis. The Delaware Valley's population of 7.2 million ranks it as the eighth-largest combined statistical area in the United States.William Penn, an English Quaker, founded the city in 1682 to serve as capital of the Pennsylvania Colony. Philadelphia played an instrumental role in the American Revolution as a meeting place for the Founding Fathers of the United States, who signed the Declaration of Independence in 1776 at the Second Continental Congress, and the Constitution at the Philadelphia Convention of 1787. Several other key events occurred in Philadelphia during the Revolutionary War including the First Continental Congress, the preservation of the Liberty Bell, the Battle of Germantown, and the Siege of Fort Mifflin. Philadelphia remained the nation's largest city until being overtaken by New York City in 1790; the city was also one of the nation's capitals during the revolution, serving as temporary U.S. capital while Washington, D.C. was under construction. In the 19th century, Philadelphia became a major industrial center and a railroad hub. The city grew from an influx of European immigrants, most of whom came from Ireland, Italy and Germany—the three largest reported ancestry groups in the city as of 2015. In the early 20th century, Philadelphia became a prime destination for African Americans during the Great Migration after the Civil War, as well as Puerto Ricans. The city's population doubled from one million to two million people between 1890 and 1950. The Philadelphia area's many universities and colleges make it a top study destination, as the city has evolved into an educational and economic hub. As of 2019, the Philadelphia metropolitan area is estimated to produce a gross metropolitan product (GMP) of $490 billion. Philadelphia is the center of economic activity in Pennsylvania and is home to five Fortune 1000 companies. The Philadelphia skyline is expanding, with a market of almost 81,900 commercial properties in 2016, including several nationally prominent skyscrapers. Philadelphia has more outdoor sculptures and murals than any other American city. Fairmount Park, when combined with the adjacent Wissahickon Valley Park in the same watershed, is one of the largest contiguous urban park areas in the United States. The city is known for its arts, culture, cuisine, and colonial history, attracting 42 million domestic tourists in 2016 who spent $6.8 billion, generating an estimated $11 billion in total economic impact in the city and surrounding four counties of Pennsylvania. Philadelphia has also emerged as a biotechnology hub.Philadelphia is the birthplace of the United States Marine Corps, and is also the home of many U.S. firsts, including the first library (1731), hospital (1751), medical school (1765), national capital (1774), stock exchange (1790), zoo (1874), and business school (1881). Philadelphia contains 67 National Historic Landmarks and the World Heritage Site of Independence Hall. The city became a member of the Organization of World Heritage Cities in 2015, as the first World Heritage City in the United States. Although Philadelphia is rapidly undergoing gentrification, the city actively maintains mitigation strategies to minimize displacement of homeowners in gentrifying neighborhoods.