Why is the study of american slavery important

Which type of constitutional power allows congress to regulate immigration and naturalization?

Why was the sixteenth amendment important to woodrow wilson’s efforts to regulate the economy? a) the sixteenth amendment lowered interest rates charged by banks. b) the sixteenth amendment allowed congress to levy an income tax c) the sixteenth amendment lowered tariffs on imported goods d) the sixteenth amendment allowed congress to break up monopolies

How did isolationism affect foreign policy?