Why didnt US declare war on Germany during World War 2?

Germany, Italy and the other minor Axis nations.

The only nation the US did declare war on was Japan, the day after Japan attacked the US Naval Base at Pearl Harbor.

Three days after the US declared war on Japan, Germany and Italy declared war against the US. That was enough to bring about a state of war between the US and Germany and Italy. There was no need for Congress to declare war back.