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 was one of the nation's capitals during the revolution, and served 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. According to the Bureau of Economic Analysis, the Philadelphia area had a gross domestic product of US$431 billion in 2016, the eighth-largest metropolitan economy in the United States. 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, and colonial history which attracted 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.
Before Europeans arrived, the Philadelphia area was home to the Lenape (Delaware) Indians in the village of Shackamaxon. The Lenape are a Native American tribe and First Nations band government. They are also called Delaware Indians, and their historical territory was along the Delaware River watershed, western Long Island, and the Lower Hudson Valley. Most Lenape were pushed out of their Delaware homeland during the 18th century by expanding European colonies, exacerbated by losses from intertribal conflicts. Lenape communities were weakened by newly introduced diseases, mainly smallpox, and violent conflict with Europeans. Iroquois people occasionally fought the Lenape. Surviving Lenape moved west into the upper Ohio River basin. The American Revolutionary War and United States' independence pushed them further west. In the 1860s, the United States government sent most Lenape remaining in the eastern United States to the Indian Territory (present-day Oklahoma and surrounding territory) under the Indian removal policy. In the 21st century, most Lenape reside in Oklahoma, with some communities living also in Wisconsin, Ontario (Canada) and their traditional homelands.
Europeans came to the Delaware Valley in the early 17th century, with the first settlements founded by the Dutch, who in 1623 built Fort Nassau on the Delaware River opposite the Schuylkill River in what is now Brooklawn, New Jersey. The Dutch considered the entire Delaware River valley to be part of their New Netherland colony. In 1638, Swedish settlers led by renegade Dutch established the colony of New Sweden at Fort Christina (present-day Wilmington, Delaware) and quickly spread out in the valley. In 1644, New Sweden supported the Susquehannocks in their military defeat of the English colony of Maryland. In 1648, the Dutch built Fort Beversreede on the west bank of the Delaware, south of the Schuylkill near the present-day Eastwick neighborhood, to reassert their dominion over the area. The Swedes responded by building Fort Nya Korsholm, or New Korsholm, after a town in Finland with a Swedish majority. In 1655, a Dutch military campaign led by New Netherland Director-General Peter Stuyvesant took control of the Swedish colony, ending its claim to independence. The Swedish and Finnish settlers continued to have their own militia, religion, and court, and to enjoy substantial autonomy under the Dutch. The English conquered the New Netherland colony in 1664, though the situation did not change substantially until 1682 when the area was included in William Penn's charter for Pennsylvania.
In 1681, in partial repayment of a debt, Charles II of England granted Penn a charter for what would become the Pennsylvania colony. Despite the royal charter, Penn bought the land from the local Lenape to be on good terms with the Native Americans and ensure peace for his colony. Penn made a treaty of friendship with Lenape chief Tammany under an elm tree at Shackamaxon, in what is now the city's Fishtown neighborhood. Penn named the city Philadelphia, which is Greek for brotherly love, derived from the Ancient Greek terms φίλος phílos (beloved, dear) and ἀδελφός adelphós (brother, brotherly). As a Quaker, Penn had experienced religious persecution and wanted his colony to be a place where anyone could worship freely. This tolerance, far more than afforded by most other colonies, led to better relations with the local native tribes and fostered Philadelphia's rapid growth into America's most important city.
Penn planned a city on the Delaware River to serve as a port and place for government. Hoping that Philadelphia would become more like an English rural town instead of a city, Penn laid out roads on a grid plan to keep houses and businesses spread far apart, with areas for gardens and orchards. The city's inhabitants did not follow Penn's plans, however, as they crowded by the Delaware River port, and subdivided and resold their lots. Before Penn left Philadelphia for the last time, he issued the Charter of 1701 establishing it as a city. Though poor at first, the city became an important trading center with tolerable living conditions by the 1750s. Benjamin Franklin, a leading citizen, helped improve city services and founded new ones, such as fire protection, a library, and one of the American colonies' first hospitals.