Frederick Jackson Turner was and is important in American history because he originated the "frontier thesis" that guided American views of history for a long time. Turner argued that the presence of the frontier made America what it was. It allowed Americans to become individualistic, self-reliant, and democratic. This thesis has been very important in American historical thinking because it has influenced the way that Americans think about themselves and the ways in which they imagine the days of the frontier and of westward expansion. In these ways, Jackson changed the way that Americans thought of themselves, their character, and where that character came from.