1957 Event Checheno-Ingush ASSR reformed in RSFSR 1957 Event Kalmyk Autonomous Region reformed in RSFSR 1957 Event Karachayevo-Cherkess Autonomous Region reestablished in RSFSR 1932 Event Kara-Kalpak Autonomous Region in RSFSR becomes Kara-Kalpak ASSR 1930 Event Mordovian Autonomous Region in RSFSR constituted 1928 Event Cherkess Autonomous Region forms in RSFSR (until 1957) 1926 Event Karachai Autonomous Region forms in RSFSR (until 1943) 1926 Event Kirghiz Autonomous Region in RSFSR becomes Kirghiz ASSR 1925 Event Kara-Kalpak Autonomous Region constituted in RSFSR 1925 Event Chuvash Autonomous Region in RSFSR becomes Chuvash ASSR 1922 Event Soviet Union organized as a federation of RSFSR, Ukrainian SSR, Belorussian SSR and Transcaucasian SSR 1921 Event Dagestan ASSR forms in RSFSR 1921 Event Mountain Autonomous Republic established in RSFSR 1920 Event Chuvash Autonomous Region forms in RSFSR 1919 Event Bashkir ASSR, in RSFSR, constituted 1918 Event Terek Autonomous Republic established in RSFSR (until 1921)
