Battlefield Chronicles: The United States' Invasion of Russia
As World War l raged on in 1917, a victory for the Entente Powers was far from guaranteed, even with the United States entering the war on the side of France, Britain, and Russia. In the Russian Empire, conditions both on and off the battlefield were steadily getting worse.
The year got off to a bad start on the war's Eastern Front, as a revolution in Russia forced Tsar Nicholas II to abdicate his throne in February. A republic was briefly established but didn't last long. Soon, Bolshevik forces led by Vladimir Lenin took over the provisional government, and by October 1917, they were in power.
By March 1918, the newly-established Soviet Union made a separate peace with Germany and the other Central Powers with the Treaty of Brest-Litovsk, taking Russia out of the war. But even the Soviet Union was far from guaranteed. The Bolshevik forces formed the Red Army to counter a coalition of Tsarists and Republicans, the White Armies.
As the White Armies fought to unseat the Soviet government, the Entente Allies decided to intervene in the Civil War. Foreign troops landed on Russian soil across the country. The United Kingdom, France, Japan, Greece, Italy, Estonia, and the United States all joined the effort to support the Whites.
On Sept. 4, 1918, the U.S. landed three infantry battalions and three engineer companies at Arkhangelsk in northern Russia to join British forces fighting there. A small number was also sent to Vladivostok to reinforce Czech and Slovak troops in the Russian far east. Their goal was to smash the Bolshevik armies and get Russia back into the war.
The U.S. troops who fought there would come to call it "The Polar Bear Expedition."
In Arkhangelsk, the American mission was simple: prevent war supplies and other material provided by Entente forces from aiding the Bolshevik war effort. But by the time the Polar Bears arrived, that material was already gone, shipped up the Dvina River with the retreating Red Army.
A force of Czechs and Slovaks are known as the “Czech Legion," were tied up fighting Bolsheviks along the Trans-Siberian Railway. This front defended by the legionnaires was hundreds of miles long and wouldn't stay defensible for very long, so the American Expeditionary Forces were sent to help relieve the Czech Legion.
A combined British and American force fought the Bolsheviks in a massive breakout from Arkhangelsk along the Dvina and the Vologda Railroad for six weeks. But their own front soon became hundreds of miles long. It was too long to maintain indefinitely, and the allied offensive soon came to a halt. To top it all off, the Russian winter was beginning to set in.
The British and Americans took a defensive posture and tried to raise an army of anti-Bolshevik volunteers from the civilian population. The effort came to nothing, and the allies had to abandon any hopes of linking up with the Czechoslovakians.
When winter started in full, the Red Army went on the offensive and pushed the combined forces back to Arkhangelsk. In November of 1918, the armistice ending World War I was signed in Versailles, but the fighting in Russia continued. Americans at home and in Russia began to question why they were still fighting. 
But getting home would be impossible as the port of Arkhangelsk had frozen up for the winter. Americans were no longer fighting for Russia; they were fighting for their own survival. They fought on for months before the U.S. Army could arrive in the port. The icebreaker Canada finally steamed into Arkhangelsk on April 17, 1919, to begin the withdrawal.
The first Americans to arrive home wouldn't get there until June 1919, almost eight months after the end of World War I. The Soviet Union eventually defeated the White Army and established itself as the new governing power in what used to be called Russia.
Remains of 125 American troops left behind in Russia would eventually be repatriated with the diplomatic and logistical support of a veterans organization that was just 20 years old: the Veterans of Foreign Wars (VFW).