Which amendment created the Electoral College and separated presidential from vice presidential elections?

The 12th Amendment is the correct answer because it specifically established the procedures for electing the President and Vice President of the United States, fundamentally changing the original process outlined in the Constitution. Prior to the 12th Amendment, the candidate receiving the most electoral votes would become President, while the runner-up would serve as Vice President. This led to complications and political conflicts, particularly in the elections of 1796 and 1800.

By ratifying the 12th Amendment in 1804, the Framers ensured that electors would cast separate ballots for President and Vice President. This change allowed for a clearer and more organized electoral process, reducing the potential for party conflict in the highest offices. The 12th Amendment thus solidified the structure of the Electoral College, which remains central to the American electoral system today.

The other amendments mentioned address entirely different issues: the 10th Amendment focuses on state powers, the 15th Amendment pertains to voting rights regardless of race, and the 19th Amendment grants women the right to vote. Hence, they do not pertain to the creation or reform of the electoral process for presidential elections.