Roosevelt still needed a joint congressional resolution after Germany and Italy declared war on the United States. The German resolution passed 88-0 in the Senate and 393-0 in the House. It formally declared the state of war and authorized the president to employ the country's naval and military forces and government resources. Sam Rayburn, H. A. Wallace and Roosevelt signed the resolution. The timing of the European announcements gave Washington notice in the morning and allowed congressional action that afternoon. These events provide the constitutional starting point for considering what a war declaration would have required without the Axis announcements.
Chapter · 48:58-51:17
Congress authorizes war after the Axis declarations
The joint resolution formally declares war and authorizes American naval, military and government resources after Germany's declaration.