On June 15, 1804, the Twelfth Amendment to the U.S. Constitution was ratified, creating separate votes in the electoral college for President and Vice-President. In prior elections, the country experienced problems with the original system in Article II, Section 1, Clause 3 of the Constitution, which failed to adequately segregate votes for President and Vice-President. This led to a tie in the 1800 election between Presidential and Vice-Presidential candidates of the same party.
Learn more about the history of the Twelfth Amendment from the University of Chicago.