What was the First American attack on Germany in World War 2?

The first attack was made by carrier based aircraft on the Japanese submarine I-170 in the vicinity of the Hawaian Islands on 10 December 1941. The I-170 was sunk.

== The first time an American unit engaged German units in combat was in North Africa in 1942. The 175th Field Artillery Battalion of the 34th Infantry Division was loaned to support the British.

(Of course there were previous examples of small commando units that carried out raids against the Germans.)