In the spring and summer of 1917, BSA organizations emerged in Minsk, Gomel, Vitebsk, Mogilev, Orsha, Bobruisk, Slutsk, Moscow, Petrograd, Saratov, and other cities of the country where Belarusians lived, as well as in parts of the Western and Northern Front, in the Baltic Fleet. By the end of the summer of 1917, the BSA had about 10 thousand members. The party included representatives of various social strata: peasants, intelligentsia, artisans, workers, soldiers, and nobility.
June 4–6, 1917, the 2nd BSA conference was held in Petrograd, where the draft of a new program was discussed (adopted at the 3rd BSA Congress on October 14–25, 1917). The party’s ultimate goal was the transition to the socialist system. The solution of the key socioeconomic issues (a division of land, nationalization of industry, etc.) was postponed until the Constituent Assembly. On the main issues, the BSA views were close to the SR program.
In the autumn of 1917, a part of the left-wing separated from the BSA, forming the Belarusian Social Democratic Labor Party (BSDLP) led by Aleksander Chervyakov. The BSDLP members fully accepted the program of the Bolsheviks and joined them. Most of the BSA opposed the establishment of Soviet power in Belarus and initiated the proclamation of the Belarusian People’s Republic (BPR) in March 1918. Several BSA members joined the BPR Rada. In June 1918, the BSA split for good.
The right-wing BSA leaders created the Belarusian Social Democratic Party (BSDP). The Central Committee of the BSDP included Joseph Lyosik, Anton and Ivan Lutskevich, etc. In June 1918, upon the initiative of the BSDP faction in the Belarusian Rada, the People’s Secretariat coalition was created (it was led by Ivan Sereda, then by Anton Lutskevich). The BSDP members prioritized the national issue, did not recognize the Socialist Soviet Republic of Belarus (SSRB), and advocated cooperation with the Polish authorities. By the beginning of 1921, they stopped operating on the territory of Soviet Belarus.
The Belarusian Party of Socialist Revolutionaries (BPSR), headed by Tomash Grib and Poluta Bodunova emerged from the Narodnik group of the BSA. It included members of local SR and left SR organizations. The BPSR supported the independence of Belarus and actively participated in the movement against the German troops. In January 1919, the BPSR leaders did not recognize the SSRB. In November 1919, Minsk announced a break with the political parties that focused on Poland. They began to get closer to the Bolsheviks but in July 1920, refused to sign the Declaration of Independence of the SSRB. Some of the party members continued to work underground, some emigrated, and the rest were subjected to repression.
In August 1918, the Belarusian Party of Socialist Federalists (BPSF) emerged from the socialist federalists of the BSF. Its Central Committee included Joseph Voronko, Aleksander Tsvikevich, Konstantin Yezovitov, Pyotr Krichevsky, and Ivan Sereda. The BPSF was in opposition to the Bolsheviks, supported the BPR, but opposed the tactics towards Germany. In December 1919, the left-wing of the BPSF joined the BPSR. At the beginning of 1921, the BPSF finally ceased its activities on the territory of Soviet Belarus.
Some of the former members of the BSA joined the Belarusian National Commissariat, a structural unit of the People’s Commissariat of Nationalities of the Russian SFSR. In January 1919, Dmitry Zhilunovich, Aleksander Chervyakov, Osip Dylo, and others joined the first SSRB government.