What era was the second half of the 19th century?

Which of the following statements is true about germany's use of u-boats?

How w.e.b. dubois wanted to improve the social and economic situation that existed for african americans during the early 19th century?

Deu 6. the federal reserve system to regulate (1) the annual federal budget (2) state sales tax rates (3) social security payments (4) the nation's money supply . .the codoral reserve system