


In 2010, Forbes rated Harrisburg as the second-best place in the U.S. Harrisburg experienced the Three Mile Island accident on March 28, 1979, in nearby Middletown. The city also hosts the annual Great American Outdoor Show, the largest of its kind in the world, among many other events. The Pennsylvania Farm Show, the largest indoor agriculture exposition in the U.S., was first held in Harrisburg in 1917 and has been held there every early-to-mid January since. These economic fluctuations contributed to Harrisburg experiencing a decline of nearly half its population between 19. In the mid-to-late 20th century, the city's economic fortunes fluctuated with its major industries consisting of government, heavy manufacturing, agriculture, and food services. During part of the 19th century, the building of the Pennsylvania Canal and later the Pennsylvania Railroad allowed Harrisburg to develop into one of the most industrialized cities in the Northeastern United States. Harrisburg played a role in American history during the Westward Migration, the American Civil War, and the Industrial Revolution. It is the larger principal city of the Harrisburg–Carlisle metropolitan statistical area, also known as the Susquehanna Valley, which had a population of 591,712 as of 2020, making it the fourth-most populous metropolitan area in Pennsylvania after the Philadelphia, Pittsburgh, and Lehigh Valley metropolitan areas. Harrisburg is situated on the east bank of the Susquehanna River. With a population of 50,135 as of 2021, Harrisburg is the ninth-largest city and 15th-largest municipality in Pennsylvania. Harrisburg is the capital city of the Commonwealth of Pennsylvania, United States, and the seat of Dauphin County.
