Pennsylvania's largest cities in terms of population as of 2015 are Philadelphia, Pittsburgh, Allentown and Erie. The state capital, Harrisburg, only makes it to number 10 on the size list. Other notable Pennsylvania cities are Gettysburg, Hershey and Levittown.
Midway between New York City and Washington, D.C., Philadelphia is a World Heritage City. Its role in history includes the signing of the Declaration of Independence and the U.S. Constitution, Quakerism, abolitionism and contributions to the Industrial Revolution, such as textiles and the steam engine. The city today is home to top medical centers, the Ivy League University of Pennsylvania, the world-class Philadelphia Museum of Art, the Philly cheesesteak and the New Year's Day Mummers Parade.
Pittsburgh is the leading city of the steel industry. Located at the confluence of three rivers, it also led in ship building, glass, aluminum and energy and environmental design. It is home to many corporate headquarters such as Alcoa, Calgon Carbon, U.S. Steel and Westinghouse Electric Company. The top-ranked schools Carnegie-Mellon and the University of Pittsburgh are in the city. Pittsburgh has earned top ratings as one of America's most livable cities.
Gettysburg is the site of the Civil War battle and the Gettysburg Address. Today Gettysburg National Park offers museums, living history and battle reenactments. Hershey is the home of Hershey chocolate and has the related tourist attractions, Hershey's Chocolate World, The Hershey Story Museum and HersheyPark amusement park. Levittown is a famous 1950s planned community of single-family ranch homes.