Frederick Jackson Turner and the frontier. A year after the Oklahoma Land Rush, the director of the U.S. Census Bureau announced that the frontier was closed. The 1890 census had shown that a frontier line, a point beyond which the population density was less than two persons per square mile, no longer existed.
I hope that helped!!!
D is the correct answer I believe
Answer:
marriages between germans and jews were prohibited
Charles V, I think. I'm not certain though.
