This talk will review the five most contentious presidential elections in American history: 1800, 1824, 1876, 2000, and 2020. It will explore related issues such as how we elect presidents, how controversies in elections tend to arise, how they get resolved, and their impact on future elections. This topic is especially pertinent in our current political era, since our elections are often close, and the nation is sharply divided. Note: This lecture is 1 hour and 15 minutes, including time for a Q&A.

