America's entry into World War I

Definition

America's entry into World War I refers to the United States' involvement in the conflict beginning in April 1917, after several years of remaining neutral. This shift was driven by factors such as unrestricted submarine warfare by Germany, the Zimmermann Telegram, and economic ties with the Allies. The entry marked a turning point in the war, as American troops and resources significantly bolstered the Allied forces against the Central Powers.

5 Must Know Facts For Your Next Test

1. The U.S. initially maintained neutrality in World War I, influenced by isolationist sentiments and a desire to avoid European conflicts.
2. The sinking of the Lusitania in 1915 by a German submarine killed 128 Americans and fueled anti-German sentiment in the U.S.
3. In March 1917, Germany resumed unrestricted submarine warfare, leading to the sinking of American merchant ships and prompting a stronger U.S. response.
4. The declaration of war against Germany came on April 6, 1917, following the interception of the Zimmermann Telegram that proposed a German-Mexican alliance.
5. The American Expeditionary Forces, led by General John J. Pershing, played a crucial role in key battles in 1918, helping to turn the tide of the war in favor of the Allies.

Review Questions

• How did unrestricted submarine warfare contribute to America's decision to enter World War I?
  • Unrestricted submarine warfare significantly impacted America's decision to enter World War I as it directly threatened American lives and commerce. After Germany resumed this aggressive tactic, American merchant ships were sunk without warning, resulting in loss of lives and goods. This blatant disregard for neutral shipping escalated tensions between the U.S. and Germany, ultimately pushing America toward intervention in the conflict.
• What role did the Zimmermann Telegram play in shaping public opinion in America regarding World War I?
  • The Zimmermann Telegram played a pivotal role in shaping American public opinion by revealing Germany's intent to ally with Mexico against the U.S. This secret communication was intercepted and decoded by British intelligence, then made public. The proposal outraged many Americans, who saw it as a direct threat to national security and sovereignty, thereby galvanizing support for entering the war against Germany.
• Evaluate how America's entry into World War I altered the course of the conflict and its aftermath.
  • America's entry into World War I fundamentally altered the course of the conflict due to its vast resources and fresh troops that significantly strengthened Allied forces. The arrival of American soldiers on European battlefields in 1918 helped halt German advances and contributed to a series of Allied victories that led to the armistice in November 1918. In the aftermath, America's role in shaping post-war treaties established it as a key player on the global stage, influencing future international relations and setting the foundation for its eventual emergence as a superpower.

Related terms

Unrestricted Submarine Warfare: A naval warfare policy where submarines sink vessels without warning, a key factor leading to America's entry into the war.

Zimmermann Telegram:

A secret diplomatic communication from Germany to Mexico proposing a military alliance against the United States, which stirred public outrage and contributed to America's decision to join the war.

Selective Service Act: Legislation passed in May 1917 that authorized the U.S. government to draft soldiers for military service, facilitating the rapid mobilization of American troops.