This chapter examines the process of American territorial expansion and settlement to the Mississippi River between the American Revolution (and even further back into British times) up until 1840. During the course of this settlement, the thirteen seaside states increased to twenty-six. This was a time when the federal government first asserted authority over the public land. The chapter first considers how early statesmen asserted sovereignty over Native Americans before discussing the issue of boundary lines between the federal government and the Indians, how the government mobilized populations for compact settlement in strategically important areas of the frontier, and how the government assumed a monopoly over the public domain and used its authority to restrain population movements. It shows that federal land policies were used by national officials to avoid being stretched too thin while maintaining strength through compactness.