The Union of Soviet Socialist Republics (Russian: Союз Советских Социалистических Республик, Soyuz Sovetskikh Sotsialisticheskikh Respublik), commonly known as the Soviet Union (Советский Союз, Sovetskiy Soyuz) and abbreviated as the U.S.S.R. (С.С.С.Р., S.S.S.R.), was a former communist nation which existed between 1922 until its dissolution in December 1991.
The Soviet Union comprised of 18 Soviet Socialist Republics. Each comprised of a distinct ethnic group.