Donald J. Trump was president of the United States when the Coronavirus Disease 2019 (COVID-19) began to spread worldwide in January 2020 and was declared a pandemic in March. The rapid spread of the deadly disease challenged the nation’s (and indeed the world’s) economic, social, medical, and political systems, and the virus played a major role in determining the outcome of the 2020 presidential election. The president and other American leaders struggled to develop and implement policies to control the spread and severity of the disease as deep divisions emerged over the effectiveness of the nation’s response.