In April 1919, President Woodrow Wilson joined other world leaders in Paris to hammer out peace terms for World War I, which had ended the previous November. The war had monopolized Wilson’s attention during his second term in office, to the point that he wouldn’t even acknowledge the 1918 influenza pandemic (often referred to as the Spanish flu at that time), which killed nearly 700,000 Americans. As John M. Barry, author of The Great Influenza, told TIME, “anything negative was viewed as hurting morale and hurting the war effort.”

Shortly after arriving in Paris, Wilson caught the flu.

Not Just a Common Cold

Behind closed doors at the Hôtel du Prince Murat, the situation was grave. The president lay in bed, wracked with coughing fits, diarrhea, and high fever, while his staff tried to make sense of his delirious rantings. As chief usher Irwin Hoover recalled, they simply couldn’t convince Wilson that the hotel was not, as he insisted, teeming with French spies.

“About this time he also acquired a peculiar notion he was personally responsible for all the property in the furnished place he was occupying,” Hoover said. (Apparently, Smithsonian reports, Wilson thought some furniture had gone missing, though it hadn’t moved at all.) “Coming from the President, whom we all knew so well, these were very funny things, and we could but surmise that something queer was happening in his mind.”

In a letter to Wilson’s private secretary, Joseph Tumulty, White House physician Cary T. Grayson explained that the illness was so sudden and severe that he “was at first suspicious that [Wilson’s] food had been tampered with.” While Grayson admitted to Tumulty that the president had indeed contracted the “treacherous” influenza—and that he was anxious about the president's condition—the doctor wasn’t nearly as forthcoming with the American people.

Woodrow Wilson with Cary T. Grayson on his left, circa 1918. Harris & Ewing Collection, Library of Congress Prints and Photographs Division // No Know Restrictions on Publication

Newspapers published frequent updates on Wilson’s convalescence, citing Grayson’s steady reassurances that their unshakeable leader was merely suffering from a cold, which was “no cause for worry.” The White House also implied that Wilson himself was somehow uniquely equipped to defeat the disease, since he “always throws off the deepest colds quickly.”

Lasting Effects and Last Words

Wilson did manage to throw off the virus, saving Grayson and the rest of the administration from having to come clean about the deception. But some people believe that the illness might have affected the outcome of the Paris Peace Conference.

As The New Yorker reported earlier this year, Wilson had wanted leniency for Germany in order to foster world peace and diplomacy. Britain and France, on the other hand, were pushing for harsher consequences—steep debt, loss of land, and French occupation in the Rhineland. The leaders were in the midst of an ongoing, heated debate when Wilson fell ill, and once he had recovered enough to resume the discussion, he quickly caved to their terms. Though we can’t say with any certainty that Wilson’s bout of influenza was related to his about-face, it is possible that it weakened his reserve.

The "Big Four" leaders at the Paris Peace Conference in May 1919. From left to right: Britain's David Lloyd George, Italy's Vittorio Orlando, France's Georges Clemenceau, and Woodrow Wilson.Bain News Service Photograph Collection, Library of Congress Prints and Photographs Division // No Known Restrictions on Publication

It also may have weakened his health overall. In October of that same year, Wilson nearly died from a stroke, which caused partial blindness and partial paralysis on his left side. Again, the details were kept from the public, and Wilson continued to preside over the country with some major help from his wife, Edith, until the end of his term in 1921.

Wilson still never addressed the 1918 flu pandemic, but his last sentence is a confirmation that he at least knew how it felt to experience the kind of total physical deterioration that a virus like the 1918 flu can cause. “I am a broken piece of machinery,” Wilson said before his death in 1924. “When the machinery is broken—I am ready.”