America entered World War One on April 6th, 1917. Up to that date, America had tried to keep out of World War One, though America had traded with nations involved in the war. But, unrestricted submarine warfare, introduced by the Germans on January 9th, 1917, was the primary issue that caused President Woodrow Wilson to ask Congress to declare war on Germany on April 2nd. Four days later, America joined World War One on the side of the Allies.

In 1914, when war was declared in Europe, America adopted a policy of neutrality and isolation. When news of trench warfare and the horrors associated with it reached the shores of America, it confirmed to the government that they had adopted the right approach. Their approach had the full support of the majority of Americans – many of whom could not believe that the civilized countries in Europe could descend into such depths as were depicted by trench warfare and the futility associated with such a strategy.

Though small groups within America – American-Germans, American-French etc – were all for some form of involvement for their own ‘side’, the bulk of Americans supported President Wilson’s approach and as a president seeking re-election in 1916, he had to listen to what the public said.

Woodrow Wilson took full control of foreign policy issues within the limits of the Constitution. Though he delegated work to members of his cabinet and others, he maintained full control over what America did in terms of foreign policy. As a student of modern history, Wilson was very aware that the causes of war were rarely black and white and that the modern European scenario was a complicated one. For this reason, he maintained America’s neutrality, as he did not believe that any of America’s interests were threatened by a European war – as long as her trade was allowed to continue unhindered.

On August 4th, 1914, Wilson officially announced that America would be neutral in World War One. That neutrality extended to a policy of ‘fairness’ – whereby American bankers could lend money to both sides in the war. Overseas trade was more complicated. Trade with both sides was permitted and merchant ships crossed the Atlantic to trade. However, a British naval blockade of the German coastline made it all but impossible for America to trade with Germany – through no fault of that country own. The British policy of blockading Germany was the primary reason for Germany ultimately introducing unrestricted submarine warfare. Germany would have claimed that Britain had forced her into taking this action.

It was Germany’s use of U-boat submarines that pushed America into a corner and ultimately to declare war. On February 4th, 1915, Germany announced that merchant shipping in a specified zone around Britain would be legitimate targets to attack. They added that this would include neutral ships because many Allied ships had taken to flying the flag of a neutral nation to assist its safety.

Wilson warned the Germans that he would hold them to account if any American ships were sunk. This threat was tested when on May 7th, 1915, the ship ‘Lusitania’ was sunk. 128 Americans on board the ship were killed. However, the ‘Lusitania’ was not an American ship and Wilson accepted the German’s change of policy – that U-boats would adopt ‘cruiser’ tactics and surface and attack a ship by guns fitted on to their decks.

The German chancellor, Bethmann-Hollweg, managed to avoid a major diplomatic issue this time but the military in Germany was adamant that the ‘cruiser’ tactic was not going to be used as it was too dangerous. In fact, what was seen as Wilson’s hard line stance, paid even greater dividends as the German government promised to compensate for any American ships that were destroyed, including the value of their cargo.

By the end of 1915, tolerable equilibrium had been reached in terms of America’s relationship with Germany. In late December 1915, Wilson sent one of his closest advisors to London, Colonel House, to see if a peace initiative could be thrashed out between Britain and Germany with America acting as an intermediary.

On February 22nd, 1916, the House-Grey Memorandum was signed which put on paper Wilson’s plan of mediation. House returned to America in good spirits and immediately set about with Wilson putting some substance into the Memorandum. The sinking by a U-boat of the paddle steamer ‘Sussex’ on March 24th, 1916, all but ended this venture. Two Americans on the ‘Sussex’ were hurt but when reports got back to America, they stated that they had been killed. The ‘Sussex’ incident was resolved and by mid-1916, the Americans seemed to have developed a more positive relationship with Germany.

The same was not true with regards to Britain. First, Britain turned its back on the Memorandum signed by its own Foreign Secretary, Sir Edward Grey. Then Britain increased its maritime activities with regards to stopping ships trading with Germany and other members of the Central Powers. Finally, the treatment of those arrested after the failed Easter Rising in Dublin in 1916 had greatly angered the influential Irish-American community on America’s east coast. To many, Britain had lost the moral high ground and to some it seemed as if Britain did not want peace at all.

On November 7th, 1916, Wilson won the presidential election. To many Americans he was still seen as a man of peace whereas his opponent, Charles Evans Hughes, was seen as a warmonger. Wilson spent the next few months trying to set up a way in which America could lead peace negotiations that would end the war. He sent out a simple question to both sides – what would it take for them to be willing to end the war? Britain and France sent back replies that stated their terms – terms that could only be met with a decisive military victory. Germany’s reply was vague and evasive.

Regardless of this, President Wilson continued to fight for peace based around the idea of a League of Nations. In mid-January 1917, he set up secret negotiations with both Britain and Germany to obtain their agreement for America’s mediation in a peace plan. Wilson had a very clear idea of what he wanted: “Peace had to be a peace of reconciliation, a peace without victory, for a victor’s peace would leave a sting, a resentment, a bitter memory upon which terms of peace would rest, not permanently, but only as upon quicksand.”

President Wilson presented a program of fourteen points to a joint session of Congress on January 8, 1918. Eight of the fourteen points treated specific territorial issues among the combatant nations. Five of the other six concerned general principles for a peaceful world: open covenants (i.e. treaties or agreements) openly arrived at; freedom of the seas; free trade; reduction of armaments; and adjustment of colonial claims based on the principles of self-determination. The fourteenth point proposed what was to become the League of Nations to guarantee the “political independence and territorial integrity [of] great and small states alike.”

On April 2, 1917, President Woodrow Wilson went before a joint session of Congress to request a declaration of war against Germany. Wilson cited Germany’s violation of its pledge to suspend unrestricted submarine warfare in the North Atlantic and the Mediterranean, as well as its attempts to entice Mexico into an alliance against the United States, as his reasons for declaring war.

On April 4, 1917, the U.S. Senate voted in support of the measure to declare war on Germany. The House concurred two days later. The United States later declared war on German ally Austria-Hungary on December 7, 1917.

To get soldiers, America had to President Wilson opposed a draft, but at the point the U.S. declared war there were fewer than 400,000 troops in the U.S. Army and National Guard together. They were in no way prepared for a major war. So, Congress passed the Selective Service Act on May 18, 1917. The act required men between the ages of 21 and 30 to register for the draft. In time, the age range was expanded to 18 to 45. Over 2.8 million were drafted through the war.

On June 26, the first 14,000 U.S. infantry troops landed in France to begin training for combat. After four years of bloody stalemate along the western front, the entrance of America’s well-supplied forces into the conflict marked a major turning point in the war and helped the Allies to victory. When the war finally ended, on November 11, 1918, more than two million American soldiers had served on the battlefields of Western Europe, and some 50,000 of them had lost their lives.

The Paris Peace Conference convened in January 1919 at Versailles just outside Paris. The conference was called to establish the terms of the peace after World War I. Though nearly thirty nations participated, the representatives of the United Kingdom, France, the United States, and Italy became known as the “Big Four.” The “Big Four” dominated the proceedings that led to the formulation of the Treaty of Versailles, a treaty that ended World War I.

The Treaty of Versailles articulated the compromises reached at the conference. It included the planned formation of the League of Nations, which would serve both as an international forum and an international collective security arrangement. U.S. President Woodrow Wilson was a strong advocate of the League as he believed it would prevent future wars.