In 1864, Lambdin P. Milligan and four others were accused of planning to steal Union weapons and invade Union prisoner-of-war camps and were sentenced to hang by a military court. However, their execution was not set until May 1865, so they were able to argue the case after the war ended. In "Ex parte Milligan" (1866), the U.S. Supreme Court decided that Congress's 1863 suspension of the writ did not empower the President to try to convict citizens before military tribunals where the civil courts were open and operational. This was one of the key Supreme Court Cases of the American Civil War that dealt with wartime civil liberties and martial law.