
Following his attendance at the Paris Peace Conference, Wilson returned home to the United States to campaign for Senate approval of the peace treaty and the League of Nations Covenant. When he was unable to secure enough support in Congress for what he wanted, he decided to appeal to the American people directly. He set off on a nation-wide speaking tour. While speaking in Pueblo, Colorado on September 25, 1919, Wilson suffered a debilitating stroke which left him partly paralyzed.
The stroke ended any chances Wilson had of making the case for the League. The United States never did ratify the Treaty of Versailles nor join the League of Nations, something that had been Wilson's concept. Wilson's health problems were attributed to the physical strain of the public speaking tour he undertook in support of ratification of Treaty of Versailles. In Pueblo, Colorado, on September 25, 1919, he collapsed and never fully recovered from the effects of the stroke he suffered.
On October 2, 1919, while at the White House, Wilson suffered another serious stroke. This one left him paralyzed on his left side, and with only partial vision in the right eye. He was confined to bed for weeks and sequestered from everyone except his wife and physician, Dr. Cary Grayson. For some months he used a wheelchair and later he required use of a cane.
Wilson never publicly admitted his incapacity, not even to his Vice-President Thomas Marshall. His wife Edith and his aide Joe Tumulty obtained the assistance of journalist, Louis Seibold, who presented a false account of an interview he allegedly had with a supposedly health President Woodrow Wilson.
During this time, Edith Wilson served as a sort of de facto acting President. She selected matters for his attention, delegated other duties to his cabinet, and made sure that no one saw him, other than those who were in on the secret. When his health improved somewhat, Wilson temporarily resumed a perfunctory attendance at cabinet meetings, but he participated little, if at all. Edith Wilson took over many routine duties and details of the Executive branch of the government. She decided which matters of state were important enough to bring to the bedridden president.
Edith later wrote:
"I studied every paper sent from the different Secretaries or Senators, and tried to digest and present in tabloid form the things that, despite my vigilance, had to go to the President. I, myself, never made a single decision regarding the disposition of public affairs. The only decision that was mine was what was important and what was not, and the very important decision of when to present matters to my husband."
One Republican senator later quipped that Edith was "the Presidentress who had fulfilled the dream of the suffragettes by changing her title from First Lady to Acting First Man." But in her memoir, appropriately titled "My Memoir", which was published in 1939, she called her role a "stewardship". She insisted that her actions had been taken only because the president's doctors told her to do so for her husband's mental health.
By February 1920, the President's true condition was finally revealed to the public. Many expressed qualms about Wilson's fitness for the presidency. At the time, domestic issues such as strikes, unemployment, inflation and the threat of Communism were all serious matters that required to be dealt with. But no one, including the first lade, the President's physician or anyone else was willing to take responsibility for the certification required by the Constitution of Wilson's "inability to discharge the powers and duties of the said office".
When all of this was going on, Wilson's Vice-President was Thomas Marshall. Wilson's closest adviser, Joseph Tumulty, did not believe Marshall was capable of being president. Edith Wilson agreed and the two conspired to to prevent Marshall from assuming the presidency. Edith Wilson disliked Marshall for what she called his "uncouthed" disposition. Tumulty and the First Lady believed that an official communication from Wilson's staff on his condition would allow Marshall to trigger the constitutional mechanism allowing him to become acting president, and made sure no such communication was ever sent.

Eventually Marshall demanded to know Wilson's status. A Baltimore Sun reporter had told Marshall that Wilson was near death, but without an official communication on Wilson's condition, Marshall believed that he could not constitutionally assume the presidency.
On October 5, Secretary of State Robert Lansing proposed that Marshall assume the presidency. Other cabinet secretaries agreed, as did Congressional leaders, including members of both the Democratic and Republican parties who sent private communications to Marshall. But Marshall was cautious about this. He consulted with his wife and his adviser Mark Thistlethwaite, and decided that he could not assume Wilson's duties.
The process for declaring a president incapacitated was unclear at that time. Marshall had hoped that Wilson would voluntarily allow his powers to devolve to the vice president, but that wasn't going to happen, given Wilson's condition and dislike for Marshall. Marshall told the cabinet that the only circumstances in which he would assume the presidency were a joint resolution of Congress calling on him to do so, or an official communication from Wilson.
Marshall tried to meet with Wilson to personally determine his condition, he was unable to do so. He relied on vague updates he received through Wilson's physician. A group of Congressional leaders initiated Marshall's requested joint resolution. But the senators who opposed the League of Nations treaty believed that as president Marshall would make several key concessions that would allow the treaty to win ratification. In order to prevent the treaty's ratification, the anti-League senators blocked the joint resolution.
On December 4, Lansing announced in a Senate committee hearing that no one in the cabinet had spoken with or seen Wilson in over sixty days. The senators supporting Marshall requested that a committee be sent to check on Wilson's condition. The news media called them the "smelling committee". The group discovered Wilson was in very poor health, but seemed to have recovered enough of his faculties to make decisions. Their report ended the need for the joint resolution.
At a Sunday church service in mid-December, a courier brought a message informing him that Wilson had died. Marshall was shocked, and rose to announce the news to the congregation. The ministers held a prayer, the congregation began singing hymns, and many people wept. Marshall and his wife went to the White House, only to learn that he had been the victim of a hoax, and that Wilson was still alive.
Marshall performed a few ceremonial functions for the remainder of Wilson's term, such as hosting foreign dignitaries like Albert I, King of the Belgians, the first European monarch to visit the United States. Edward, Prince of Wales, the future monarch of the United Kingdom, spent two days with Marshall and received a personal tour of Washington from him. But it was First Lady Edith Wilson who performed most routine duties of government by reviewing all of Wilson's communications and deciding what he would be presented with and what she would delegate to others.
The resulting lack of leadership allowed the administration's opponents to prevent ratification of the League of Nations treaty. Marshall personally supported the treaty's adoption, but recommended several changes, including the requirement that all parties to it acknowledge the Monroe Doctrine.

Wilson began to recover by the end of 1919, but he remained secluded for the remainder of his term. He refused to accept changes to the treaty. Marshall was prevented from meeting with Wilson right up until his final day in office.