Question

Which action by germany prompted the united states to enter world war 1

Answer 1

Germany had formally surrendered on November 11, 1918, and all nations had agreed to stop fighting while the terms of peace were negotiated. On June 28, 1919, Germany and the Allied Nations (including Britain, France, Italy and Russia) signed the Treaty of Versailles, formally ending the war. 

this was alittle section on google here is the link i found this on 

www.americaslibrary.gov/jb/jazz/jb_jazz_ww1_1.html