In mid-march four unarmed American merchantmen were sunk by German U-boat killing thirty-sex persons. On April 2, 1917 in the Chamber of the House of the representatives Wilson called upon Congress to recognize the state of war that had been ´thrust´ upon the United States. The Congress response on 4 and 6 1917 was that ´the state of war … which has thus been thrust upon the United States is hereby formally