Ex Parte Milligan U.S. Supreme Court case that took place in 1866. It represented the first test of the President's power to authorize trials for civilians by military tribunal rather than through the system of civil courts. In 1863, President Abraham Lincoln suspended the writ of habeas corpus in situations where individuals were to be tried for acts of revolt against the military. Lambdin P. Milligan was arrested in Indiana by military authorities, tried for inciting rebellion and other acts...