American history

Between the wars (1918–1941)

1. Russian Revolution

The so-called Polar Bear Expedition was the involvement of U.S. troops, during the tail end of World War I and the Russian Revolution, in fighting the Bolsheviks in Arkhangelsk, Russia in 1918 and 1919, despite having been sent there on the pretext of halting a German advance on the eastern front of the war. American volunteers also participated on the Polish side in the Polish-Soviet War, forming a core of the elite fighter unit, the Kosciuszko Squadron.

2. Spanish Civil War

The Abraham Lincoln Brigade was an organization of United States volunteers supporting or fighting for the anti-fascist Spanish Republican forces in the Spanish Civil War as part of the International Brigade.

The name "brigade" is something of a misnomer, as there were several American battalions organized under the Fifteenth International Brigade of the Spanish Republican army at this time. This brigade was loosely organized by the Comintern and was made up of volunteers from nations around the globe.

Most of the people making up the Abraham Lincoln Brigade were official members of the Communist Party USA or affiliated with other socialist organizations. The IWW, or "Wobblies", were lightly represented.

However, the brigade was made up of volunteers from all walks of American life, and from all socio-economic classes. It was the first unit of soldiers made up of Americans to have an African-American officer, Oliver Law, lead white soldiers.