There is authorized to be constructed by the Secretary of the Interior upon the Jefferson National Expansion Memorial National Historic Site,¹ Saint Louis, Missouri, an appropriate national memorial to those persons who made possible the territorial expansion of the United States, including President Thomas Jefferson and his aides, Livingston and Monroe, who negotiated the Louisiana Purchase, the great explorers, Lewis and Clark, and the hardy hunters, trappers, frontiersmen, pioneers, and others who contributed to such expansion.