What two events caused the united states to declare war on germany?

Three things that led the Congress and President Roosevelt to declare war on Germany were:

• Japan attacked the United States. This was the impetus that finally allowed the president and congress to declare war on both Germany and Japan.
• Britain was desperate for help. Winston Churchill had sent numerous requests for the assistance of the US.
• Hitler's invasion and murders in other countries moved the US to stop Hitler in his tracks.