Otto Wels was a German politician who served as a member of the Reichstag from 1912 to 1933 and as the chairman of the Social Democratic Party (SPD) from 1919 until his death in 1939. He was the military commander of Berlin in the turbulent early days of the German Revolution of 1918–1919, and during the 1920 Kapp Putsch he was instrumental in organizing the general strike that helped defeat the anti-republican putschists. Near the end of the Weimar Republic's life, however, he saw the futility of calling a general strike against the 1932 Prussian coup d'état because of the mass unemployment of the Great Depression.