A left-wing political party that advocated socialist transformations and the national autonomy of Belarus. The first Belarusian National Party. Created in the winter of 1902–1903 based on national educational circles of students in Minsk, St. Petersburg, and Vilna. The original name was the Belarusian Revolutionary Assembly (Hramada). The first program (1903) provided for the overthrow of the autocracy, the right of nations to self-determination, the elimination of private land ownership, the transfer of factories and plants to workers. In 1905, together with the Socialist Revolutionaries (SRs), it created the Belarusian Peasant Union. In 1906, clarifications were made to the BSA program on the national land fund creation. During the Revolution of 1905–1907, the BSA organized strikes and rallies in the Belarusian regions, acting jointly with the Social Revolutionaries, the Russian Social Democratic Labor Party (RSDLP), and the Bund. In 1907, the party stopped its dynamic political activity, continuing to publish Nasha Niva legal newspaper in Belarusian.

After the February Revolution, the BSA resumed its activities, confirmed its socialist commitment, the demands for the autonomy of Belarus within the borders of the Russian Democratic Republic, and the development of Belarusian culture, language, and school. On March 25, 1917, the BSA conference in Minsk supported the Provisional Government to continue the war and carry out the reformist transformations, demanded the election of state officials, the establishment of a progressive tax, land use according to the labor norm with public land ownership. In a coalition with other national parties, the BSA announced the creation of the Belarusian National Committee (BNC). Later, the BNC was replaced by the Central Rada of Belarusian organizations, in which the BSA took a leading position.