Answer:
The lasting impact did Frederick Jackson Turner have on the United States is that D: He influenced political leaders and thinkers of the time period.
Explanation:
Turner’s main ‘’Frontier Thesis’’ was to expand America in the west direction by conquering the uninhabited lands. According to him, with this expansion, more industries could be grown on these lands and citizens would become more independent or self-sufficient. He said the strength of America lies in its land and its frontier.
His theories were quite influential in America’s history. He believed in existence of free land and advancing America’s settlement. Also, as economic power will increase, political power would also increase.