The finish of the Walking Purchase which forces the cession of 1.2 million acres (4,860 km²) of Lenape-Delaware tribal land to the Pennsylvania Colony.

The Walking Purchase (or Walking Treaty) was a 1737 agreement between the Penn family, the original proprietors of the Province of Pennsylvania in the colonial era (later the American state of the Commonwealth of Pennsylvania after 1776) and the Lenape native Indians (also known as the Delaware Indians). By it the Penn family and proprietors claimed an area of 1,200,000 acres (4,860 km2) along the northern reaches of the Delaware River at the northeastern boundary between the Province of Pennsylvania and the West New Jersey area to the east of the Province of New Jersey (later after the American Revolutionary War [1775–1783], as the State of New Jersey) and forced the Lenape to vacate it. The Lenape appeal to the Iroquois Indian tribe further north for aid on the issue was refused.

In the legal suit and court case, Delaware Nation v. Pennsylvania (2004), the Delaware nation] (one of three later federally recognized Lenape tribes) and its descendants in the 21st century claimed 314 acres (1.27 km2) of land included in the original so-called "purchase" in 1737, but the U.S. District Court granted the Commonwealth's motion to dismiss. It ruled that the case was nonjusticiable, even if the Delaware Nation's allegations of fraud were true. This ruling held through several appealed actions made through several levels of the United States courts of appeals. The Supreme Court of the United States refused to hear the case, which had the effect of upholding the lower appeals courts' decision.