the French encountered the Erie, Illinois, and Miami tribes in the late 1600's as they first explored the lands west and south of Lake Erie
Source: Library of Congress, Map of the Indian tribes of North America, about 1600 A.D. along the Atlantic, & about 1800 A.D. westwardly (Albert Gallatin, 1836)
Before Europeans provided firearms to the Iroquous (Huadenosaunee), what became known in the 1700's as the Northwest Territory was occupied primarily by the Fox and Mascouten ("Fire People") in the northwest, the Illinois and Miami tribes in the west, and the Erie in the east.
the territory morthwest of the Ohio River was occupied by various Natve American groups ever since the ice sheet retreated over 10,000 years ago
Source: Library of Congress, Partie occidentale de la Nouvelle France ou du Canada (by Jacques Nicolas Bellin, 1755)
Native American tribes manipulated the French and British until 1763, changing alliances to get trading benefits and preserve territory
Source: Library of Congress, A general map of the middle British colonies, in America (Lewis Evans, 1755)
Access to the Ohio River and the Northwest Territory beyond it was easiest by way of the Forks of the Ohio, which developed into modern Pittsburgh. The French and Indian War started in 1754 after the Ohio Company built a fort there, the French chased them away, and George Washington led Virginia troops westward to force the French to withdraw. After a brief engagement at Jumonville Glen, Washington retreated towards Virginia. On the way home he build Fort Necessity and surrendered there.
That same route was followed by British General Edward Braddock in 1755. After his defeat, General John Forbes led the third campaign in 1758 to capture the Forks of the Ohio. He chose to build a road from the Susquehanna River westward through Pennsylvania, rather than use Alexandria as his supply base and assemble his forces at Fort Cumberland in Maryland. Washington and other Virginians recognized that the Forbes Road would provide direct access to the Ohio River. The military decision by General Forbes was a gift to Pennsylvania traders and land speculators seeking to profit off western lands.
topography blocked easy access from Virginia to lands along the Ohio River; the best route was via the Forks of the Ohio
Source: Library of Congress, A general map of the middle British colonies, in America (Lewis Evans, 1755)
four states claimed the lands of the Northwest Territory, based on colonial charters or conquest
Source: Library of Congress, The comprehensive series, historical-geographical maps of the United States (1919)
the Land Ordinance of 1785 and the Northwest Ordinance of 1787 guided disposal of the public domain and creation of new states from the Northwest Territory
Source: Library of Congress, The comprehensive series, historical-geographical maps of the United States (1919)