Fort Pitt (now Pittsburgh) at the source of the Ohio River became the main base for settlers moving into the Northwest Territory.
The War of 1812 cut off the supply of British goods, stimulating American industry.
The French built Fort Duquesne based on La Salle's 1669 claims.
The French and Indian War, the North American front of the Seven Years' War, began with the future Pittsburgh as its center.
British General Edward Braddock was dispatched with Major George Washington as his aide to take Fort Duquesne.
By the 1840s, Pittsburgh was one of the largest cities west of the Allegheny Mountains.
During this period, the powerful nations of the Iroquois Confederacy, based in New York, had maintained control of much of the Ohio Valley as hunting grounds by right of conquest after defeating other tribes.
By the terms of the 1768 Treaty of Fort Stanwix, the Penns were allowed to purchase the modern region from the Iroquois.
The metropolitan population of 2,353,045 is the largest in both the Ohio Valley and Appalachia, the second-largest in Pennsylvania (behind Philadelphia), and the 26th-largest in the U. Located at the confluence of the Allegheny, Monongahela, and Ohio River, Pittsburgh is known as both "the Steel City" for its more than 300 steel-related businesses, and as the "City of Bridges" for its 446 bridges.
The city features 30 skyscrapers, two inclines, a pre-revolutionary fortification and the Point State Park at the confluence of the rivers.