Woodrow Wilson was more focused on the end of World War I than a flu virus that was making its way around the globe, ultimately sickening hundreds of thousands of Americans, including the president himself. 

George W. Bush stood with a bullhorn on a pile of rubble after the 9/11 attacks on lower Manhattan and promised that the people who were responsible “will hear all of us soon.”

Barack Obama was in office for just a few months when the first reports came in about the H1N1 virus, which would eventually be declared a pandemic like today's new coronavirus.

Most American presidents will confront a crisis—or crises—before they leave office, whether it is a natural disaster, war, economic downturn, public health threat or terrorism.

What matters is how they respond, historians say.

"The number one thing a president can do in a moment like this is try to calm the nation," said Julian Zelizer, a presidential historian at Princeton University.