Abstract This dissertation examined the policy of American settlers toward Native peoples in the United States as one of the most complex issues in modern American history, as it was closely connected to the emergence of the new state and to the political, military, and economic transformations that followed the War of Independence, this policy developed within an expansionist context characterized by the pursuit of control over land and resources and the reorganization of geographical space in ways that served settler interests, in contrast to the marginalization of Indigenous presence and the erosion of their political and social systems, historical evidence demonstrated that relations between the two sides did not rest on fixed foundations of peace or conflict alone, but rather evolved through a combination of temporary treaties, armed confrontations, and legal measures that collectively contributed to the reshaping of the demographic and political map of North America. The period following 1783 emerged as a critical turning point in the manner by which American settlers dealt with Native peoples, as policy shifted from a colonial framework subordinate to the British Crown to a national policy led by an emerging federal government that sought to consolidate internal sovereignty and extend its authority over frontier regions, this transformation coincided with the intensification of westward internal migration and the growing pressure on tribal lands, which rendered Indigenous affairs an integral component of the state-building project rather than a mere border or security issue, and this shift was reflected in the proliferation of treaties, legislation, and military campaigns aimed at reorganizing relations with Native tribes according to a logic of dominance and control. The nature of the dissertation entitled The Policy of American Settlers toward Native Peoples in the United States up to 1820 required its division into an introduction, five chapters, a conclusion, a list of sources and