Final answer:
Before the 12th Amendment, the Electoral College selected two candidates - one for President and one for Vice President. The 12th Amendment changed the system by creating a separate election for President and Vice President within the Electoral College.
Step-by-step explanation:
Before the 12th Amendment, the Electoral College worked by selecting two candidates - one for President and one for Vice President. Each state had the same number of electors as the number of people that served in the United States Congress from that state. The electors could vote for any two candidates, as long as one of those candidates was not from their home state. The candidate with the highest number of votes became President, and the candidate with the second highest number of votes became Vice President. If no candidate received a majority, then the House of Representatives, voting by state, would decide.
The 12th Amendment, ratified in 1804, changed the system. It created a separate election for President and Vice President within the Electoral College. This was done to avoid situations like the tie between Thomas Jefferson and Aaron Burr. The amendment also set out ways to choose a winner if no one received a majority of the electoral votes.