Why was the election of 1800 decided in the House of Representatives?

The 12th amendment requires this process.
No candidate receives a majority in the electoral college.
Both candidates were from the same party.
No candidate wanted to be vice president.

The election of 1800 was decided in the House of Representatives because no candidate received a majority in the electoral college. According to the Constitution, if no candidate garners a majority of the electoral votes, the House of Representatives is responsible for choosing the president from the top three candidates. In this particular election, Thomas Jefferson and Aaron Burr, both from the same party (Democratic-Republican), received the same number of electoral votes, leading to a tie. The situation was further complicated by the fact that neither candidate wanted to be vice president, which eventually led to 35 tie-breaking votes in the House before Thomas Jefferson was elected as the third President of the United States.