the Iroquois confederated to reduce warfare between the five tribes, before the Tuscarora migrated north to join them as the sixth tribe
Source: Library of Congress, A Map of the Country of the Five Nations, belonging to the Province of New York... (by Cadwallader Colden, 1747)
Five Iroquois tribes, the Mohawk, Oneida, Cayuga, Onondaga and Seneca, established the Haudenosaunee (hoe-den-o-SHOW-nee) Confederacy and dominated the territory west of the Hudson River. According to the origin story, a Huron known as Dekanawidah (the Peacemaker) convinced an Onondaga who was living with the Mohawks to establish a Great Law of Peace among the tribes. That leader was Hiawatha.2
The British colonists often descried those who came south and raided through Virginia and North Carolina as the "Seneca," but more than just the most-western Iroquois were involved.
When William Byrd II was surveying the dividing line between Virginia and North Carolina in 1733, he reached Upper and Lower Saura Towns on the Dan River. They had been unoccupied for decades, since the Siouan-speaking residents had fled southeastward to escape further raids by the Iroquois:1
William Byrd II found in 1733 that raids by the Iroquois had displaced Siouan-speaking groups from the Virginia-Carolina Piedmont, and the Saura towns on the Dan River had been abandoned
Source: Library of Congress, A map of the most inhabited part of Virginia containing the whole province of Maryland with part of Pensilvania, New Jersey and North Carolina (by Joshua Fry and Peter Jefferson, 1755)
The removal of the Tuscarora from North Carolina around 1720 added a sixth nation to the Haudenosaunee Confederacy.
the Tuscarora migrated from North Carolina into territory of the Onondaga and Oneida
Source: Smithsonian Institution, Haudenosaunee Guide for Educators
The Haudenosaunee Confederacy fragmented in the Revolutionary War. The British recruited the Seneca and Onondaga, while the American rebels recruited the Mohawk and Oneida. A smallpox epidemic in 1777 killed 90 of the top leaders and caused the Central Council fire to be extinguished. That left the individual nations free to operate independently, without a need to reach consensus on which side to support as British forces fought rebellious colonists.
At the bloody battle of Oriskany, different nations allied with different sides and fought each other. The failure to stay united enabled the Americans to displace the Iroquois tribes from their homelands.3
the Two Row Belt, supposedly created in 1613, is claimed to represent a 1613 agreement between the Five Nations and the Dutch in New York to trade together but live in separate communities, like people in two canoes traveling together
Map Source: Six Nations (Haudenosaunee) & the Haldimand Tract: Beliefs vs. Facts
after defeat of the Dutch, the New York colony claimed all the land between the North (Hudson) River and South (Delaware) River, shown here as R. du Sud
Map Source: Library of Congress, Amerique septentrionale
in the 1768 Treaty of Ft. Stanwix, the boundary defined by the Proclamation of 1763 was revised and the Iroquois relinquished claims to lands south of the Ohio River - but the primary territory occupied by the Oneida, Onondaga, Cayuga, Seneca, and Tuscarora were still (theoretically) off-limits to colonial settlement
Source: National Park Service, Oriskany: A Place Of Great Sadness (p.xiv)
in the 1750's the British claimed sovereignty over lands west of the Susquehanna River which the Iroquois had been conquered
Source: Library of Congress, A map of the British and French dominions in North America, with the roads, distances, limits, and extent of the settlements (John Mitchell, 1755)
the Iroquois conquered nations to the south and west, and controlled the fur trade with the Dutch and the British at Albany
Source: A map of the country of the Five Nations belonging to the Province of New York, and of the lakes near which the nations of far Indians live, with part of Canada (by William Bradford, 1727)
the British claim to territory of the Six Nations extended all the way to Lake Michigan (Quadoghe, now Chicago) and the Mississippi River
Source: Library of Congress, A map of the British and French dominions in North America, with the roads, distances, limits, and extent of the settlements (John Mitchell, 1755)
John Mitchell asserted in 1755 that "none have ever thought fit to dispute" British claims of sovereignty over the Ohio Territory based on conquest of the Iroquois - but the French and Indian War erupted because of such a dispute
Source: Library of Congress, A map of the British and French dominions in North America, with the roads, distances, limits, and extent of the settlements (John Mitchell, 1755)
Europeans claimed the Iroquois acquired by conquest the rights to lands extending as far as the Mississippi River (shaded in green)
Source: Library of Congress, An accurate map of North America. Describing and distinguishing the British, Spanish and French dominions on this great continent; according to the definitive treaty concluded at Paris 10th Feby. 1763 (Emanuel Bowen, 1767)
extension of Quebec's boundaries in 1774 did not affect Iroquois land claims in New York or Native American claims south of the Ohio River
Source: Perry-Castaneda Library Map Collection, The British Colonies in North America, 1763-1775 (in Historical Atlas by William R. Shepherd, 1923)
by 1804, New York mapmakers reduced Iroquois land claims to one small reservation area
Source: David Rumsey Map Collection, A Map of the State Of New York (Simeon DeWitt, 1804)
the Haudenosaunee (Iroquois Confederacy, the Six Nations) occupied territory around the Finger Lakes before being displaced by the colonists in the 1700's
Source: Library of Congress, Map of Ho-De-No-Sau-Nee-Ga: or the territories of the People of the Long House in 1720 (by Lewis Henry Morgan, 1720)