June 30, 1839 – Cinque led a successful slave revolt on the ship Amistad.
June 30, 1885 – The Chicago Streetcar Strike began on this day and continued through July 7.
June 30, 1912 – A Modern School, modeled after the ones started by Francisco Ferer in Spain, was created by the Grupo Luz in Mexico City.
June 30 1918 – Eugene Debs was arrested in Cleveland for interfering with army and navy recruiting.
June 30, 1922 – One million railway shop men struck.
(All from the Daily Bleed)