Ex parte Milligan

US Supreme Court decision 1866 that attended to the issue of the jurisdiction of military tribunals in areas where civilian courts are operating. Milligan, an Indiana citizen sentenced by a military tribunal to hang for secessionist activities, petitioned for a writ of habeas corpus on the grounds that as a civilian he was not subject to military law. The Court ruled 5-4 in favour of Milligan, holding that neither the US president nor Congress had the right to impose martial law outside of a war zone.