The Union of Soviet Socialist Republics (USSR) comprised 15 republics:
1. Russian Soviet Federative Socialist Republic (RSFSR) - which later became the Russian Federation after the dissolution of the USSR.
2. Ukrainian Soviet Socialist Republic (UkrSSR) - which is now Ukraine.
3. Byelorussian Soviet Socialist Republic (Byelorussian SSR) - which is now Belarus.
4. Kazakh Soviet Socialist Republic (Kazakh SSR) - which is now Kazakhstan.
5. Uzbek Soviet Socialist Republic (Uzbek SSR) - which is now Uzbekistan.
6. Georgian Soviet Socialist Republic (Georgian SSR) - which is now Georgia.
7. Azerbaijani Soviet Socialist Republic (Azerbaijani SSR) - which is now Azerbaijan.
8. Lithuanian Soviet Socialist Republic (Lithuanian SSR) - which is now Lithuania.
9. Moldavian Soviet Socialist Republic (Moldavian SSR) - which is now Moldova.
10. Latvian Soviet Socialist Republic (Latvian SSR) - which is now Latvia.
11. Kirghiz Soviet Socialist Republic (Kirghiz SSR) - which is now Kyrgyzstan.
12. Tajik Soviet Socialist Republic (Tajik SSR) - which is now Tajikistan.
13. Armenian Soviet Socialist Republic (Armenian SSR) - which is now Armenia.
14. Turkmen Soviet Socialist Republic (Turkmen SSR) - which is now Turkmenistan.
15. Estonian Soviet Socialist Republic (Estonian SSR) - which is now Estonia.
These republics were semi-autonomous entities within the USSR, though in practice, their autonomy varied throughout the history of the Soviet Union.
https://en.wikipedia.org/wiki/Soviet_Union
