Two grants were made over the same parcel of land.
The first was made from two Indian tribes to P in 1773.
A second grant was made by the United States to D.
Procedural History
District Court of Illinois found for D.
SCOTUS affirmed for D.
Issues
Do the Indians have the power to give, and can private individuals receive from Indians, title to land?
Holding/Rule
The Indians do not have the power to grant land, therefore, a title obtained from the Indians cannot be sustained in the Courts of the United States.
Reasoning
When the Europeans discovered America, they established the principle that discovery gave title to the government by whose subjects or authority the discovery was made. Other nations were excluded.
The nation that made the discovery had control over the regulations with the Indians.
Power of the Indians to dispose of the land as they pleased was denied by the fundamental principle that title belonged to the discoverer.
English government was very clear that it was taking possession of the land when it made the discovery of the Americas, and that principle has continued to be recognized.
In Virginia, the exclusive right to purchase any lands from the Indians belonged to the government.
Some land was ceded to the U.S. government, and the government has the exclusive right to extinguish their title.
It is not for the courts to question this right of title, since so much history says that the U.S. has the right to grant the land, not the Indians.
Generally, the conqueror gets to determine the limits of title, and to enforce them. It usually makes sense for the conquered inhabitants to be able to regain rights to property. However, because the Indians were "fierce savages," the European governments could not give them back title, because they were ready to repel all attempts to control them. Therefore, it was necessary for the Europeans to adapt and create this new rule.
Therefore, Indian inhabitants are considered merely occupants, who had the right to possess the land, but who were incapable of transferring the absolute title to others.
Notes
Six traditional sticks in the bundle of sticks:
The right to possess
The right to exclude
The right to transfer
The right to use
The right to enjoy fruits
The right to alter
Conquest necessarily diminishes the property rights of conquered peoples and the courts are in no position to decide in favor of pre-conquest claims.