On April 2, 1917, President Woodrow Wilson went before a joint session of Congress to request a declaration of war against Germany. ... Germany's resumption of submarine attacks on passenger and merchant ships in 1917 became the primary motivation behind Wilson's decision to lead the United States into World War I.

Why did US declare war on Germany ww2?

On 11 December 1941, four days after the Japanese attack on Pearl Harbor and the United States declaration of war against the Japanese Empire, Nazi Germany declared war against the United States, in response to what was claimed to be a series of provocations by the United States government when the U.S. was still ...

Why did the US fight against Germany?

In April President Woodrow Wilson asked Congress for a declaration of war against Germany, largely in response to Berlin's policy of unrestricted submarine warfare (sinking merchant ships without warning). The declaration was passed by 82 votes to 6 in the Senate, and by 373 to 50 in the House of Representatives.