A. Investigation PlanThis investigation will analyze to what extent the Zimmermann Telegram influenced the United States' decision to enter World War I on the side of the Allies? To do this, the investigation will examine attempts by the United States to avoid involvement in the war and how the German government responded to these attempts. What the Germans hoped to achieve by sending the telegram and how American opinion on the war was influenced by the telegram's publication will also be explored, with particular attention given to President Woodrow Wilson. The investigation will also consider the impact of Germany's resumption of unrestricted submarine warfare on the American decision. Summary of Evidence When World War I broke out in 1914, President Woodrow Wilson immediately declared the United States neutral, imploring citizens "to be impartial in thought and action" (Wilson, Message to Congress). Wilson then began his two-year campaign to ensure both the continued neutrality of the United States and a “peace without victory” in Europe (Baker 24). Wilson succeeded in keeping the United States out of European affairs until early 1915, when Germany announced that it would begin a policy of unrestricted submarine warfare in the waters around the British Isles (Clements and Cheezum 37). A few months later, on May 7, German submarines sank the British liner Lusitania without warning (Tuchman 64). President Wilson responded by demanding that Germany promise to abandon unrestricted submarine warfare, and by late 1915 the Germans relented (Katz 32). Later, when Germany proclaimed that it would resume unrestricted submarine warfare, Wilson again demanded that they abandon such "unlawful tacts... middle of paper ... Alex, Mary Childress and Marylin Childress. “The Zimmermann Telegram.” National Archives and Records Administration, April 4, 1981. Web. March 28, 2014. • Clements, Kendrick A. and Eric A. Woodrow Wilson. : CQ, 2003. Print.• Fitzpatrick, Sheila. The Russian Revolution. New York: Oxford University Press, 1994. Print • Katz, Friedrich. Chicago: University of Chicago, 1981. Print (p. 50) • Knight, Peter. Conspiracy Theories in American History: An Encyclopedia. Vol. 2. Santa Barbara, CA: ABC-CLIO, 2003. Printed.• Wilson, Woodrow. "Message to Congress." 63rd Cong., 2nd Sess. Senate House, Washington, DC. Address, • Tuchman, Barbara Wertheim. The Zimmermann telegram. New York: Macmillan, 1966. Print