Which constitutional amendment set up the current system where is senators are elected by popular vote

Why was the treaty of versailles harsh on germany?

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

What was the effect of the industrial revolution on the working class?