Treaty on the Creation of the USSR on 30 December 1922 by a conference of delegations from the Russian SFSR, the Transcaucasian SFSR, the Ukrainian SSR and the Byelorussian SSR. The Treaty and the Declaration were confirmed by the 1st Congress of Soviets of the USSR and signed by heads of delegations Mikhail Kalinin, Mikhail Tskhakaya, Mikhail Frunze and Grigory Petrovsky, Aleksandr Chervyakov respectively on December 30, 1922. The treaty provided flexibility to admit new members. Therefore, by 1940 the Soviet Union grew from the founding four republics to 15 republics. On 8 December 1991, Russian, Ukrainian and Belarusian Presidents signed the Belavezha Accords. The agreement declared
Russians in the Baltic states as the war drew to a close. Immediately after the war, a major influx from other USSR republics primarily of ethnic Russians took place in the Baltic states as part of a "de facto" process of Russification. These new migrants supported the industrialization of Latvia's economy. Most were factory and construction workers who settled in major urban areas. The influx included the establishment of military bases and associated personnel with the Baltic states now comprising the USSR's "de facto" western frontier bordering the Baltic Sea. Many military chose to remain upon retirement, attracted by higher living standards as compared to