i think hawai
The first US forces and Allied forces was done in Siciliy in 1943. However it was not the first attack in the European Theater of Operations. They fought in Northern Africa before they went after the Germans in Sicily, then Italy. I must clarfiy that the US and England were conducting Air Raids on Europe prior to the landings on Europe.
They attacked the colonies of Vichy France in Algeria as part of Operation Torch
The Attack of Pearl Harbor ( December 7th 1941 ) caused the U.S. to be in WW2
Italy
North Africa
attack by japan on pearl harbor
The American Army first offensive action was in North Africa. The US Navy first offensive move was to send submarines out against the Japanese Navy.
In Europe; the US reinforced the British & French in the trenches.
Save Great Britain FIRST; Britain will support ALL US Military basing & supplies; save Europe next.
Feudalism takes hold
The US attacked Fortress Europe along with the other Allied armies on D Day to defeat the Nazi occupiers. This started on June 6, 1944.