The RSFSR, or the Russian Soviet Federative Socialist Republic, was the largest and most significant constituent of the former Soviet Union. Established in 1917 after the October Revolution, it served as the first socialist state in the world. The RSFSR played a crucial role in the formation of the USSR in 1922, which united several republics under a centralized government. The RSFSR was characterized by its commitment to Marxist-Leninist ideology and aimed to create a classless society. It underwent significant political and economic changes, including the nationalization of industries and land redistribution. The RSFSR existed until the dissolution of the Soviet Union in 1991, marking the end of its socialist experiment.