The worst president of the United States is widely considered to be James Buchanan. Historians often label Buchanan as the worst due to his failure to effectively address the sectional tensions that led to the Civil War. His inaction and policies aggravated the divisions in the country, ultimately resulting in the dissolution of the Union

. Other presidents frequently ranked among the worst include Andrew Johnson, who was impeached and opposed Reconstruction efforts to help newly freed slaves; Donald Trump, criticized for his handling of the COVID-19 pandemic, ethical controversies, and inciting the January 6 Capitol attack; Franklin Pierce; William Henry Harrison; Warren G. Harding, known for scandals like Teapot Dome; and Herbert Hoover, whose presidency saw the onset of the Great Depression

. Among these, James Buchanan consistently ranks at the very bottom in multiple expert polls and historical rankings, making him the most commonly cited "worst" U.S. president