Who determined the winner of the presidential election of 1800?

The winner of the presidential election of 1800 was determined by the House of Representatives.

The presidential election of 1800 was one of the most contentious in American history. The election was between Thomas Jefferson and Aaron Burr. Both candidates received the same number of votes in the Electoral College, leading to a tie. According to the 12th Amendment of the United States Constitution, in the event of a tie in the Electoral College, the House of Representatives is required to decide the election.