Final answer:
The Union of Soviet Socialist Republics (USSR) was the country formed after the Russian Civil War ended in 1922, marking the victory of the Bolsheviks and the establishment of a Soviet state which lasted until 1991.
Step-by-step explanation:
The country that was formed after the Russian Civil War ended in 1922 is the Union of Soviet Socialist Republics (USSR). This formation was the culmination of the Bolshevik victory over various opposition forces in the civil war, where the Bolsheviks, led by Vladimir Lenin, defeated the White Army aided by foreign influences such as British, French, and U.S. troops.
The USSR constituted various Soviet republics under a centralized government and lasted until its official dissolution in 1991. Following World War II, the Soviet Union emerged as a global superpower and was instrumental in shaping the geopolitical landscape of the 20th century, which included the tension-filled Cold War era.