April 13

Roosevelt meets William Howard Taft for the first time in five years, when both serve as pallbearers at the funeral of Professor Thomas Lounsbury, a literary historian at Yale. They exchange a brief greeting but otherwise do not speak.

May 7

The RMS Lusitania, a British ocean liner, is sunk by a torpedo from a German U-boat. 1,198 civilians are killed, including 128 Americans

May 9

While in the middle of testifying in the Barnes Libel Trial, Roosevelt authors the article “Murder on the High Seas!” regarding the sinking of the Lusitania. It will be published in Metropolitan magazine. Roosevelt demands that the United States must take immediate action against Germany

June 17

Roosevelt corresponds with his friend, the British statesman Arthur Hamilton Lee, 1st Viscount Lee of Fareham. He expresses a sort of admiration of Germany’s industriousness, and distress that the United States and other European nations have not yet risen to match them. He is disgusted with pacifists, and with President Wilson in particular for his statement about being “too proud to fight.” He wishes he and his sons were already fighting, and notes his plans to raise a regiment of Rough Riders to fight in the trenches.

September 1

After British and American outrage erupts over the sinking of Lusitania, Arabic, and other ships, Germany pledges an end to unrestricted submarine warfare. They agree to no longer sink passenger liners, and merchant ships would be sunk only if they carried contraband.

Roosevelt publishes America and the World War, an analysis of the causes of the war and the urgent need for preparedness and action. Like many of his pieces, it is also a polemic against pacifists.

January 28

In an answer to President Wilson’s “Peace Without Victory” speech to Congress, delivered January 22, Roosevelt says “Peace without victory is the natural ideal of the man who is too proud to fight. In the event of war it is the only kind of peace open to the nation whose governors and leaders are too proud to fight and too foolish to prepare.”

February 1

In an effort to disrupt supply lines enough to force a British surrender, Germany resumes unrestricted submarine warfare.

February 12

In his ongoing correspondence with his close friend Henry Cabot Lodge, Roosevelt expresses doubts that Wilson could be convinced to declare war under any circumstances. Still, he promises that if he is allowed to raise a volunteer regiment, that he would serve Wilson’s administration “with single-minded loyalty.”

April 6

Due to the resumption of unrestricted submarine warfare, and other factors such as Germany’s influence over Latin America, the United States declares war on Germany, entering the Great War on the side of the Allied Powers.

April 10

Roosevelt calls on President Wilson at the White House to personally make his case for raising a Rough Rider regiment to fight on the Western front. Although cold at first, they soon become friendly and speak for 45 minutes. Despite pushback on the idea from President Wilson and Secretary of War Newton D. Baker, Roosevelt will continue to lobby.

May 18 – 19

President Wilson signs the Selective Service Act, making a public statement the next day. Although it gave the President the power to call up to a half million volunteers, Wilson chose not to as he believed volunteers not up to the task. In a telegram to Roosevelt making a final denial of his request, Wilson says that the decision wasn’t personal. Roosevelt still took it deeply personally.

June 5

The New York Bible Society distributes pocket bibles to American troops containing a message from Theodore Roosevelt. The theme, taken from Micah 6:8, is “Do justice; love mercy, walk humbly.”

June

The first waves of American troops, soon called “Doughboys” for reasons unknown, begin to land in Europe

July 5

Major General John J. Pershing forms the American Expeditionary Forces in Chaumont, France.

August

Roosevelt’s oldest son, Major Theodore “Ted” Roosevelt, Jr., is given command of a battalion in the 26th Infantry Regiment. He will eventually command the entire regiment. His brother Archibald “Archie” Roosevelt also serves in the regiment as a Captain.

September

Roosevelt’s son Kermit, who was already serving in the British armed forces, is commissioned a Captain in the Corps of Royal Engineers and serves in Iraq.

October 23

At sunrise, American forces fire their first artillery shot of the war from their position on a hill overlooking Bathelémont, France.

Roosevelt publishes The Foes of Our Own Household, an essay collection arguing that America’s enemies are not just foreign actors, but those Americans “who oppose preparedness in our military and our industrial life; the business or political corruptionist or reactionary and the reckless demagogue who is is nominal opponent; the man of wealth and greed who cares for nothing but profits, and the sinister creature who plus upon and inflames the passions of envy and violence; the hard materialist, the self-indulgent lover of ease and pleasure, and the silly sentimentalist – all these are the permanent foes of our own household.”

January 6

Theodore Roosevelt dies in his sleep at Sagamore Hill, his country estate on Long Island, New York. He was sixty years old. It is often said that the heartbreak of losing Quentin contributed to his death.

September 25

After delivering a lengthy speech in Pueblo, Colorado, President Wilson collapses from the stress of his whistle-stop tour. His health never recovers.

March 19

The United States Senate rejects the Treaty of Versailles for the second and final time. Perhaps its greatest opponent was Roosevelt’s close friend Senator Henry Cabot Lodge, who wrote a document with fourteen points of his own, called the Lodge Reservations. Lodge was in favor of joining the League of Nations as a concept, but was concerned that the proposal as written threatened United States sovereignty.

July 2

President Warren G. Harding signs the Knox-Porter Resolution, which officially declares an end to the war between the United States and Germany.