The USA joined the first world war during the end of the great war. Before they joined they were sending volunteers to the French, and British. This helped bring the war to an end faster. Once it was known that the Germans would fail, the Americans joined the British and French. This was to help in taking the German menace down. This was viewed as cowardly to some people, wondering why the united states didn’t join the commonwealth before the Germans and Austrians were near defeat.
The United States' role in the "Great War" was somewhat akin to the deus ex machina trope. The nation joined in 1917 at a point when war had already been raging for almost three years, with Europe having lost more men than in all the wars of the previous three centuries. While not all Americans were for the war effort, a vast amount were, as positive sentiments towards Great Britain and the Allies (as well as negative sentiments towards Germany) were already strong. As the Allies prepared their counterattack at the Marne River, commander Marshal Ferdinand Foch used the inexperienced, yet courageous American soldiers to fill gaps in his ranks. Reinforcements from the U.S. were met with joy, and when a force of 2 million American soldiers arrived at the Second Battle of the Marne, the exhausted German forces began their retreat. American involvement in the war was what finally tipped the scale in favor of victory for the Allies. The nation may have lost less lives than others, but its role was what finally brought the sad, senseless killing to a close.
The US's role in WWI was to provide reinforcements for the Allies. American soldiers were used bu Marshal Ferdinand Foch to fill his ranks.
America's role in WW1 was to aid the allies in defeating the Germans. They were one of the countries that had the least casualties.
Now, up until just before the U.S. declared war on April 6th, 1917, the U.S. had desperately tried to stay neutral, but ties to Britain, propaganda, the sinking of ships by German U-boats, and a German attempt in the Zimmermann Note to get Mexico to declare war on the U.S. pushed the U.S. to getting involved. The United States' role in the "Great War" was somewhat akin to the deus ex machina (God from the Machine) trope. The nation joined in 1917 at a point when war had already been raging for almost three years, with Europe having lost more men than in all the wars of the previous three centuries. While not all Americans were for the war effort, a vast amount were, as positive sentiments towards Great Britain and the Allies (as well as negative sentiments towards Germany) were already strong.
When the US joined World War I on the Allies' side in 1917, the fighting had already been going on for nearly three years. With the United States finally in the war, the balance, it seemed, was tipped in the Allies' favor. Germany had driven hard at the beginning in an attempt to quickly crush France on the one front and then rush to the other front to crush Russia. But their plan failed miserably. Towards the very end, when Russia withdrew from the war, Germany made a final push toward Paris to finish France off. Victory soon seemed within reach. BUT by that time, Germany's efforts had left their men and supplies alike thoroughly exhausted and drained. Their military was weak. Now, Allies had a huge advantage, in addition to Germany's weakness, - millions of fresh American troops, not to mention the American supplies. These were the United States' most valuable contributions to WWI, and they are what turned the tides and won the war for the Allies.
Throughout the war, the United States government vowed to stay in a neutral position. Eventually this changed because the Germans sunk a British passenger vessel that was carrying over 1,000 people. Woodrow Wilson wanted to remain neutral but Germany said they would continue to attack passenger ship. This forced the US into the war. WW1 ended 2 years later with the Treaty of Versailles.
Up until April 6th, 1917, America had adopted a policy of neutrality and decided against joining the war. However, it was Germany’s unrestricted submarine warfare that ultimately pushed the United States to enter the war and join sides with the Allies.
In WW1, the US provided reinforcements to the allies where needed and helped finally tip the scales just enough to the point where the allies could win the war.