During the 19th century, Pennsylvania grew its northwestern, northeastern, and southwestern borders, and Pittsburgh emerged as of the nation's largest and most prominent cities for a period of time.
During the 20th century, after the Great Depression of the 1930s and World War II in the 1940s, Pennsylvania moved towards the service and financial industries economically and became a swing state politically.
Archaeologists generally believe that the first settlement of the Americas occurred at least 15,000 years ago during the last glacial period, though it is unclear when humans first entered present-day Pennsylvania.
There is an open debate in the archaeological community regarding when the ancestors of Native Americans expanded across the two continents to the tip of South America, with the range of estimates being 30,000 and 10,500 years ago.
[1] The Meadowcroft Rockshelter contains the earliest known signs of human activity in Pennsylvania, and perhaps all of North America,[2] as it contains the remains of a civilization that existed over 10,000 years ago and possibly pre-dated the Clovis culture.
We know from archaeology that the Monongahela had a far more vast territory at the time[6][page needed] and the Iroquois Book of Rites shows that there were Siouans along Lake Erie's southern shores as well.
[11] They were fragmented into three groups during the Beaver Wars, the Petun of New York, the Wyandot of Ohio, and the Tiontatecaga of the Kanawha River in southern West Virginia.
During that time, the highly influential Mohawks seceded from the Iroquois Confederacy and the remaining four tribes—Seneca, Cayuga, Onondaga and Oneida—began attacking into Ohio, destroying the Petun and other tribes, then the Erie.
They sold off much of their remaining, extended lands to the English, but kept a large section along the Susquahanna River for themselves, they allowed refugees of other tribes to settle in towns, such as Shamokin, Lenape, Tutelo, Saponi, Piscataway, and Nanticoke.
[3] Like the other indigenous peoples of the Americas, the Native Americans of Pennsylvania suffered from a massive loss in population caused by disease following the beginning of the Columbian Exchange in 1492.
European exploration of North America continued in the 16th century, and the area now known as Pennsylvania was mapped by the French and labeled L'arcadia, or "wooded coast", during Giovanni da Verrazzano's voyage in 1524.
In 1643, New Sweden Governor Johan Björnsson Printz established Fort Nya Gothenburg, the first European settlement in Pennsylvania, on Tinicum Island.
Following the voyages of Giovanni da Verrazzano and Jacques Cartier, the French established a permanent colony in New France in the 17th century to exploit the North American fur trade.
During the 16th, 17th, and 18th centuries, the French expanded New France across present day Eastern Canada into the Great Lakes region, and colonized the areas around the Mississippi River as well.
Many of the settlers worshiped a brand of Christianity disfavored by the government of their homeland, including Huguenots, Puritans, Calvinists, Mennonites, and Catholics, who migrated to colonial-era Pennsylvania to exercise their religion freely.
The conflict began near the present site of Uniontown, Pennsylvania when a company of Virginia militia under the command of George Washington ambushed a French force at the Battle of Jumonville Glen in 1754.
The dispute was finally settled, and military relief sent, when the owners of the proprietary lands sent 5,000 pounds to the colonial government, on condition that it was considered a free gift and not a down payment on taxes.
Native American tribes ceased to pose a military threat to European settlers in Pennsylvania after the conclusion of the Northwest Indian War in 1795.
[30] After elections in May 1776 returned old guard Assemblymen to office, the Second Continental Congress encouraged Pennsylvania to call delegates together to discuss a new form of governance.
After the Continental Army's defeat at the Battle of Brandywine in Chadds Ford Township on September 11, 1777, the revolutionary capital of Philadelphia was left defenseless and American patriots began preparing for what they saw as an imminent British attack on the city.
It authorized the sale and distribution of the large remaining tracts of land east and west of the Allegheny River in hopes of sparking development of the vast territory.
West Allegheny district was made up of lands in Erie, Crawford, Warren, and Venango counties, relatively good investments at the time.
After the failure of the Crittenden Compromise, the secession of the South, and the Battle of Fort Sumter, the Civil War began with Pennsylvania as a key member of the Union.
However, easily the most famous and important military engagement in Pennsylvania was the Battle of Gettysburg, which is considered by many historians to be the major turning point of the Civil War.
[44] The growth of industry eventually provided middle-class incomes to working-class households, after the development of labor unions helped them gain living wages.
During this period, Pittsburgh emerged as an important center of industry and technological innovation, and George Westinghouse became one of the preeminent inventors of the United States.
The Great Depression finally broke the lock on Republican power in the state, as Democrat Franklin Roosevelt won Pennsylvania's electoral votes in all three of his re-election campaigns.
[56] This prevented the state from receiving federal funds for Works Progress Administration projects and making it difficult to lower the extremely high unemployment rate.
After learning from family members via airphone of the earlier attacks on the World Trade Center, the passengers on board revolted against the hijackers and fought for control of the plane, causing it to crash.
Both Allentown and Pittsburgh are considered part of the Rust Belt, a region of the United States negatively impacted by deindustrialization in the late 20th century.