What happened with Frederick Jackson Turner and the 1890 census?

Frederick Jackson Turner presented his influential "Frontier Thesis" in 1893, arguing that the American frontier had shaped the nation's character and democracy. The 1890 census marked the official end of the frontier era, as it declared that there was no longer a discernible line of settlement. This prompted Turner to assert that the closing of the frontier would have significant implications for American identity and future development, leading to a shift in focus from westward expansion to urbanization and industrialization.