Twenty-five years after the Declaration of Independence was first signed, the foreign territory beyond the Mississippi River remained vast, largely undiscovered terrain to the U.S. government. The land was sparsely populated by various Native American tribes as well as by occasional explorers and trappers from Spain, France, Britain, and the United States. In 1803, President Thomas Jefferson proposed sending an exploratory team to investigate the territory. In making his request for a small, specialized group of military personnel, dubbed the Corps of Discovery, to be used for exploration, Jefferson marked a new era in U.S. history: While governmental sponsorship of exploration had been used in other nations, Jefferson’s request was the first made by a president of the United States.