In 1893 he founded the American Railway Union and led it in a secondary strike on behalf of the Pullman workers in 1894 (see pullman strike). The strike was broken by the intervention of federal troops and Debs was imprisoned in 1895 for conspiracy. Together with Victor Berger, Morris Hillquit, and others, he formed the Socialist Party of America (1901) and stood as its presidential candidate. A leading pacifist, he was briefly imprisoned for discouraging recruitment to the US armed services in World War I.