After the Bolsheviks signed a separate peace treaty with Germany in 1918, the Allied Powers sent several expeditions to Russia in an attempt to prevent Allied supplied artillery and ammunition from falling into German or Bolshevik hands during the ongoing Russian Civil War. Olympia was part of the Northern Expedition. She deployed an armed landing force of her crew to the town of Murmansk, a refugee camp, and to Archangel, an Allied supply depot, where they defended these small towns from both the Bolsheviks and the Germans. Olympia's crew were the first armed Americans to ever land on Russian soil.
By November 1918, the Bolshevik army began to overtake the expeditionary forces and a general evacuation was ordered. The last American Ambassador to Tsarist Russia, David R. Francis, was put aboard Olympia, along with dozens of Army wounded as Dewey's old flagship hastily escaped to England. Consequently, the newly formed Soviet Union, fuming over the United States' involvement, broke off relations until the first American-Soviet Ambassadors were appointed in 1933.