When did the united states declare war on germany?
No context provided
When did the united states declare war on germany during WWI?
April 6, 1917
No context provided
When did the united states declare war on germany during WWII?
December 11, 1941
Declaration of war by the United States
https://en.wikipedia.org/wiki/Declaration%20of%20war%20by%20the%20United%20States
A declaration of war is a formal declaration issued by a national government indicating that a state of war exists between that nation and another. 
Declaration of war by the United States
The United States has formally declared war against foreign nations in five separate wars, each upon prior request by the President of the United States. Four of those five declarations came after hostilities had begun
Declaration of war by the United States
A declaration of war is a formal declaration issued by a national government indicating that a state of war exists between that nation and another. The United States has formally declared war against foreign nations in five separate wars, each upon prior request by the President of the United States. Four of those five declarations came after hostilities had begun. Of those five, the United States declared war on Germany during WWI on April 6, 1917 and during WWII the United States declared war on Germany on December 11, 1941.