What is closing of frontier?

The "closing of the frontier" refers to the historical moment in the late 19th century when the American West was deemed fully settled, marking the end of westward expansion. This concept was popularized by historian Frederick Jackson Turner in his 1893 essay, where he argued that the frontier played a crucial role in shaping American democracy and character. The declaration of the frontier's closure signaled a transition in American identity, as the nation shifted focus from expansion to urbanization and industrialization. It also raised questions about the implications for Native American populations and the future of American society.