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
1991 Soviet Union referendum People's Deputies of the USSR in accordance with the law on the referendum of the USSR" On January 16, 1991 the Supreme Council USSR decided that to: An official referendum had been held in Estonia on 3 March 1991 on whether to re-establish the Estonian republic that had been occupied by the Soviet Union in 1940. The result was 77.8% in favour of re-establishing the Estonian republic. Latvia also held an official referendum on 3 March 1991, when the overwhelming majority voted to re-establish the independent Latvian republic. Consequently, in these republics pro-Soviet front-organisations organised voluntary referendums without official sanction.