how did germany's use of unrestricted submarine warfare lead to american entry into ww1
On April 4, 1917, the U.S. Senate voted in support of the measure to declare war on Germany. The House concurred two days later. The United States later declared war on Austria-Hungary on December 7, 1917.Germany's resumption of submarine attacks on passenger and merchant ships in 1917 was the primary motivation behind Wilson's decision to lead the United States into World War I.n April 4, 1917, the U.S. Senate voted in support of the measure to declare war on Germany. The House concurred two days later. The United States later declared war on Austria-Hungary on December 7, 1917.