Jefferson’s vision for the Republic and the continent was linked to a particular understanding of the relationship between Native peoples and the land. From his viewpoint, Native peoples could claim a title to their homelands, but they did not own that land as private property. Jefferson assumed a natural law legal perspective, derived from social contract theory, that Natives could claim aboriginal title, or right of occupancy, on their territory, but they did not exercise dominion over it. European powers, and later the United States, made this claim because they asserted that Native peoples lived in a state of nature—that is, they were not part of the civilized world. North America was terra nullius, a legal concept dating back to the Roman Empire designating territory as vacant or unoccupied. Declaring North America terra nullius implied that the land had never been properly cultivated or truly settled. It remained, in effect, in a state of nature, the condition in which it existed at the beginning of time.
As early as the seventeenth century, these ideas about natural law and the state of nature informed Anglo-American understandings of private property. At the beginning of time, all the world was a commons whose resources were available to everyone. When human beings applied their labor to the things derived from this commons, the effort resulted in the creation of private property. A tree could be transformed into a table and chairs, making these items the possessions solely of their creator. A plot of land, similarly, could be transformed into a farm—with built structures, plowed fields and planted crops, and fenced enclosures—and entailed as private property. The cultivation of land thus carved out parcels of this shared landscape as private property, transforming the commons into a built or improved environment, a process accelerated by the creation and circulation of currency. In this increasingly complex setting, men and women were compelled to leave the state of nature and enter into civil society in order to protect their property. This was the social contract articulated most clearly by the English philosopher John Locke. Individuals gave up a portion of their rights, creating a government or sovereign designated to act on behalf of all members of society to ensure the rule of law and to protect the individual right to property and the pursuit thereof. In forming civil society, humanity left the state of nature and entered a world of laws and civil institutions designed to protect their rights in property. Appropriating the resources of the commons, men, particularly male heads of household, created civilization.