The U.S. Supreme Court ruling in Johnson v. McIntosh established the basic principles that govern American Indian property rights to this day. In the case, more than one Anglo-American purchaser claimed title to the same land in what is now southern Illinois. The Piankeshaw Indians had deeded the land twice--once to speculators in 1775, and again, thirty years later, to the United States by treaty. The Court decided in favor of William McIntosh, who had bought the land from the U.S. government. Writing for the majority, Chief Justice John Marshall declared that the "discovery"...