Today, Philadelphia’s manufacturing sector has diversified into pharmaceuticals, automotive parts and others, while its old industries have declined. At the heart of an urban area with a population of more than 6 million people, Philadelphia is an important centre of finance, insurance and health education and research—and is still a major port. Philadelphia is the only World Heritage City in the United States.

By the early 20th century, Pittsburgh accounted for up to half of the national steel output. But during de-industrialization in the 1980s, massive layoffs and mill closures took place. Since then, the city has successfully shifted its economy to education, tourism, energy research and finance, along with high technology such as robotics.

Consultant: Nicholas Harris

History of Pennsylvania

before 17th century
The area of Pennsylvania is home to Native American peoples including the Delaware (Lenape), Susquehannock, Iroquois, Erie, Shawnee and others

1638
Swedish settlers establish the New Sweden Colony on the site of present-day Wilmington, Delaware. New Sweden controls the lower Delaware River region (parts of present-day Delaware, New Jersey and Pennsylvania)

1643
New Sweden Governor Johan Printz, establishes Fort Nya Gothenburg, the first European settlement in Pennsylvania, on Tinicum Island in the Delaware River

1655
During the Second Northern War, the Dutch under Peter Stuyvesant, operating out of New Amsterdam (later, New York), capture New Sweden

1664
King Charles II of England grants his brother James, Duke of York, lands that include parts of today's Pennsylvania. This conflicts with the Dutch claim to the same area

1665–67
During the Second Anglo-Dutch War, the English take control of the Dutch colonies in North America

1674
At the end of the Third Anglo-Dutch War, the Treaty of Westminster permanently confirms England's control of the region

1681
King Charles II grants a land charter for the Province of Pennsylvania to William Penn to repay a debt owing to William's father, Admiral William Penn. The younger William Penn establishes a government at Uppland (renamed Chester) and orders the founding of the City of Brotherly Love—Philadelphia—which is laid out near the confluence of the Delaware and Schuylkill rivers

1682
Penn meets with Tammany, chief of the Delaware tribes, and signs a treaty that promotes long-lasting goodwill between the Native Americans and the European settlers

late 17th century
Immigration of Europeans, attracted by the promise of religious freedom granted by Pennsylvania’s constitution (Frame of Government). They include English and Welsh Quakers, and German Mennonites, Amish, Moravians and Lutherans

1718
Death of William Penn; his rights of ownership are passed to his heirs

1720s
Scots-Irish settlers begin colonizing the Cumberland Valley and lands further west

1750s
Resentful of encroachment on their lands, Native Americans ally with the French, who have been fortifying their positions in the Ohio valley, part of New France

1754
French establish Fort Duquesne at the confluence of the Allegheny and Monongahela rivers

1754–63
French and indian War fought between the colonies of Britain and those of New France together with its Native American allies

1758
The French eventually abandon Fort Duquesne to British and American forces; it is taken over, renamed Fort Pitt and developed as the future city of Pittsburgh

1763
Treaty of Paris: Britain's victory in the French and Indian War secures Pennsylvania's western frontier

1763
Royal Proclamation bans colonization beyond the Appalachian Mountains, in an effort to prevent colonists settling lands which the Native Americans consider their own

1763–66
Pontiac's Rebellion: an uprising by Native Americans led by the Ottawa (Odawa) chief Pontiac, attempting to drive the British out of the Great Lakes area, including western Pennsylvania, is crushed by the British

1765
Stamp Act Congress, the first meeting of the Thirteen Colonies: Delegate John Dickinson of Philadelphia writes the Declaration of Rights and Grievances

1774
Founding Fathers of the United States convene in Philadelphia at the First Continental Congress

1776
Declaration of Independence is adopted by the Second Continental Congress meeting at the Pennsylvania State House (Independence Hall) in Philadelphia (4th July)

1776
Commonwealth of Pennsylvania is created, with a new state constitution

1776
George Washington leads American troops across the Delaware River from Pennsylvania to launch a surprise attack against the Hessian forces (hired by the British) at Trenton, New Jersey

1777
The US Constitution is drafted and signed at the Pennsylvania State House

1777
The state is invaded by British troops, with battles fought on the Brandywine and at Germantown

1777–78
Valley Forge, near Philadelphia, serves as General George Washington's headquarters during the winter

1787
Pennsylvania becomes the second state after Delaware to ratify the US Constitution

1784
Acceptance of the Mason-Dixon line establishes an agreed border with Maryland and, later, Virginia

1787
Border with New York agreed; Pennsylvania gains control of northwestern Pennsylvania from the Iroquois League

1792
Pennsylvania purchases the Erie Triangle from the US federal government

1834
Pennsylvania completes construction on the Main Line of Public Works, a railway and canal system that stretches across southern Pennsylvania, connecting Philadelphia with Pittsburgh

1859
The first oil well is dug at Titusville

1863
Battle of Gettysburg, which turns the tide of the Civil War in the Union’s favour, is fought in the state. The Union army halts Confederate General Robert E. Lee's invasion of the North

late 19th century–early 20th century
Growth of industry: Pennsylvania is home to some of the largest steel companies in the world, while Hershey and Heinz factories are also established in the state. Millions of immigrants, especially from southern and eastern Europe, pour into Pennsylvania to work in the steel mills and coal mines, while many African Americans also migrate to the state from the south

1889
Johnstown Flood: the South Fork Dam bursts after heavy rain and destroys the town of Johnstown, killing over 2200 inhabitants

1923
President Calvin Coolidge establishes the Allegheny National Forest

1979
Pennsyvlania narrowly avoids a catastrophe as an accident at the Three Mile Island nuclear facility near Harrisburg results in a partial meltdown

late 20th century
The state is hard hit by the decline and restructuring of the steel industry and other heavy industries. With job losses comes significant population decline, especially in Philadelphia and Pittsburgh

2001
During the September 11 terrorist attacks on the US, United Airlines Flight 93 crashes into a field in Stonycreek Township, near Shanksville, Pennsylvania, killing all 40 civilians and four al-Qaeda hijackers on board. The hijackers intended to fly the plane to Washington, D.C. and crash it into either the Capitol or the White House

2018
Mass shooting at the Tree of Life–Or L'Simcha Congregation, a synagogue in the Squirrel Hill neighbourhood of Pittsburgh. A lone gunman kills eleven people and wounds six, including several Holocaust survivors. It is the deadliest attack ever on the Jewish community in the United States.