On April 7th, 1917, the United States of America entered the First World War.
Since the outbreak of the war in 1914, the American public had been largely in favour of neutrality during the unprecedented global conflict, which witnessed over 10 million deaths. However, opinion shifted substantially as the consequences of WW1 became gradually apparent. Ethnic, cultural and historical ties made American’s generally more supportive of Great Britain (although this cannot be said for Irish-Americans, as Anglo-Irish relations were at an all-time low due to the question of Irish Independence); in this sense, it was always relatively clear which side of the conflict the US would support. The prevailing view in America of Germany soured through the course of the war, as word of the atrocities and massacres conducted by the German Empire reached the New World.
The President, Woodrow Wilson, made an ongoing effort to maintain neutrality for the first 2 and a half years of the war. This balancing act placed great pressure on the President who, an idealist at heart, wanted to achieve world peace. Nevertheless, on April 7th, 1917, America entered the war.
A variety of factors spurred the USA’s entry onto the battlefield. Of course, the aforementioned factor of public opinion played a decisive role. Upon the realisation of the severity of WW1, the American public began to acknowledge the inevitable impact which the war would have on world history. Peaceful routes had been exhausted and, from here, it become clear that military intervention would be the only way to secure the ideals of liberty, democracy and freedom globally (the war had already had a profound impact on American politics and society, as a resurgent sense of nationalism emerged). Inevitably, the economy was another significant factor. Infamously, American countless businesses made billions in WW1 by selling arms to the Allies. Known as the ‘Merchants of Death’, these businesses often operated, due to the size of the financial exchanges and the volatility of foreign currency, using credit. In order to see that repayments were made, the indebted nations still had to exist. In this sense, the American war effort was motivated as a means to ensure the survival of their debtors.
Famously, the USA entered WW2 following the Japanese attack of Pearl Harbor in 1941, after 2 years of maintaining a delicate line of neutrality. Similarly, the catalyst for the US’ entry into WW1 was an, arguably, minor hostility from a would-be adversary. In January 1917, the German Empire adopted a policy of unrestricted submarine warfare. This policy entailed sinking any vessel without warning, regardless of who the ship belonged to. Germany were well aware of the consequences which this would have; indeed, they recognised that they would be sinking American vessels in the North Atlantic. Over the next 3 months, several ships originating from the US were sunk. Sparks flew in Congress between isolationists (who wanted to keep the US out of the war) and those in line with the President who increasingly saw the necessity of military intervention. In an effort to improve their position against the USA, the German’s attempted to organise an alliance with Mexico. At this point in time, relations between the US and Mexico were fierce due to the volatility of North American territory until the turn of the century. As such, the Kaiser’s government felt that an alliance with Mexico could be made with relative ease. The German’s dispatched the Zimmerman Telegram to Mexico, outlining their plans and the conditions of an alliance; including an offer to pay any of Mexico’s expenses for the war. Alas, British intelligence intercepted the telegram and immediately passed it to the White House.
By the end of March, public opinion had swayed to disgust – by this point, the American public resented Germany. The ongoing attacks on shipping vessels and the information that Germany had tried to make an alliance with Mexico (the White House informed the press of the Zimmerman Telegraph in late February) pushed Wilson into decisive action; on April 2nd, the President asked Congress for a declaration of war. Five days later, Congress approved.