During the Russian Revolution of 1905, Kalinin worked for the Bolshevik party and on the staff of the Central Union of Metal Workers. He later became active on behalf of the RSDLP in Tiflis, Georgia (now Tbilisi), Reval, Estonia (now Tallinn), and Moscow. In April 1906 he served as a delegate at the 4th Congress of the Russian Social Democratic Labour Party.