why was the election of 1800 decided in the house of representatives

The election of 1800 was decided in the House of Representatives because no candidate received a majority in the Electoral College. In that election, Thomas Jefferson and Aaron Burr both received the same number of electoral votes, resulting in a tie. According to the rules established by the Constitution at that time, when no candidate receives a majority of electoral votes, the election is then decided by the House of Representatives. This situation ultimately led to the election of Jefferson as President after several ballots in the House.

The 12th Amendment, which was ratified in 1804, later changed the process to prevent such a tie from occurring by establishing separate ballots for President and Vice President, but it was not in effect during the 1800 election. The other options provided, including the assertion that both candidates were from the same party and that no candidate wanted to be vice president, do not accurately describe the reasons for the House's involvement in that election.