Answer:
The sinking of the British Lusitania liner, with the lost of the lives of over a hundred Americans by a German submarine, and the revelation of the Zimmerman Note or Zimmerman Telegram, in which the German government offered to help Mexico win back the territories ceded to the USA after the Mexican-American War if it joined the German side, are the direct reasons for the American declaration of war on Germany in WWI.
Explanation:
