The frontier refers to the edge of settled land in a country, particularly in the context of the United States during the 19th century. It represents the boundary between civilization and wilderness, where explorers, settlers, and indigenous peoples interacted. The concept of the frontier played a significant role in shaping American identity and expansion. In American history, the Homestead Act of 1862 encouraged westward migration by providing land to settlers. This movement led to the establishment of new communities and the development of agriculture, but it also resulted in conflicts with Native American tribes and significant environmental changes.