When the united states entered world war ll in europe, where were american force first sent on a major offensive?

Northern Europe.

Explanation:

For the first time, American entered into World War II when they enter Greenland which became part of German as it invaded Denmark in 1940. The hostility began after Americans captured and destroyed German weather station in the east coast of Greenland in 1941. The weather stations were necessary for Germans because stations provided  U-boats (Nazi) with information about weather conditions in parts of Europe. German occupation ended in Greenland in 1944 when German technicians captured.

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