Pearl Harbor.
The first official battle of World War II involving overt US military presence was the Battle of Pearl Harbor.
The first battle for the US was Pearl Harbor.
Our first offensive for the pacific war the battle inGuadalcanal
Midway
Kesserine Pass?
The first naval battle of the Civil War happened on April 13, 1861. This naval battle took place at Fort Sumter.
june 6, 1944
The battle for Normandy didn't happen until June 1944 but the US was involved in many battles elsewhere in the world before that .
The Battle of Midway .
The Battle Of Iwo Jima
The Battle of the Philippines .
Well I don't know if this answers your question,or at least part of it,but the Battle of Kursk was the biggest battle in World War 2.Followed by the Battle of Prussia.The 5th biggest was the Battle of Berlin.Hope this answers your question.=)