American North Russia Expeditionary Force patch, type 1

The Polar Bear Expedition (also known as the Northern Russian Expedition, the American North Russia Expeditionary Force - ANREF or the American Expeditionary Force North Russia - AEFNR) was a contingent of about 5,000 United States Army troops that landed in Arkhangelsk, Russia as part of the Allied intervention in the Russian Civil War and fought the Red Army in the surrounding region during the period of September 1918 through to July 1919.