The war formally started when Archduke Ferdinand, of Austria-Hungary was killed by Serbians on June 28, 1914. With this assassination, Austria declared war on Serbia and within days, Germany joined in, declaring war on first Russia then France. With the passage of time, other countries started entering the conflict with United States initially declaring that it would remain neutral. This neutrality policy however didn't work when United States noticed that its people were being killed by Germany and that the latter was resorting to unfair means. On April 6, 1917, United States finally joined the Allies against German forces. With United States and Britain launching massive military attacks against the Central Powers, Germany soon lost its powerful place in the war and by July of 1918, it was clear that Allies would win the war. The war came to an end when Allies defeated Germany at Argonne Forest Battle and the Treaty of Versailles was signed.
United States did not want to join the conflict that had been rocking the world since 1914. Most Americans also supported government's policy and decided they wanted to stay out of war until 1917 when after a series of unfair German war tactics, President Woodrow Wilson decided to join the Allies and United States formally entered the war. The most important event that many believed triggered United States' entry was the 1915 sinking of British ocean liner Lusitania which resulted in the death of 128 Americans. This ship had been deliberately sunk by German soldiers to restrict and block the supply of food to British soldiers on the front. While the President had previously been remained staunchly against the war, he used some outrages like the sinking of the ship as an excuse to enter the war and secure victory for the Allies. It was for some a war by the kings against the kings. On April 2, 1917, President Woodrow Wilson called an extraordinary session of Congress. The word had already leaked out the President was considering joining the war and pacifist staunchly opposed this action. They blocked the roads that were to take President to the Capitol from the White House. But the Sixty-fifth session did finally take place without much trouble at the appointed day and time. The President addressed Congress and explained his reasons for entering the war. He said:
"I have called the Congress into extraordinary session because there are serious, very serious, choices of policy to be made, and made immediately, which it was neither right nor constitutionally permissible that I should assume the responsibility of making.
On the third of February last I officially laid before you the extraordinary announcement of the Imperial German Government that on and after the first day of February it was its purpose to put aside all restraints of law or of humanity and use its submarines to sink every vessel that sought to approach either the ports of Great Britain and Ireland or the western coasts of Europe or any of the ports controlled by the enemies of Germany within the Mediterranean..The new policy has swept every restriction aside. Vessels of every kind, whatever their flag, their character, their cargo, their destination, their errand,