Ex Parte Milligan, 71 U.S. 2 (1866)

The Milligan opinion, issued just after the Civil War ended, held that Lambdin Milligan’s trial by military commission was unconstitutional. Vehemently denounced by Republicans who viewed it as a threat to military reconstruction in the South, and somewhat limited by its own facts and by subsequent cases, the opinion still stands as one of the Supreme Court’s most important decisions on civil liberties and the limits of military authority over civilians.

Milligan, a lawyer practicing in southern Indiana, was an outspoken critic of both President Lincoln and Indiana’s Republican Governor Oliver P. Morton. A Democrat who unsuccessfully sought his party’s nomination for governor in 1860, Milligan opposed the war and infringements of civil liberties by state and federal officials. After 1862, Democrats controlled both houses of the Indiana legislature. State politics became extremely partisan as the 1864 presidential and gubernatorial elections drew near, and Democrats and Republicans alike formed secret societies to support their parties. Milligan’s association with one such society, the Sons of Liberty, led to his subsequent arrest and trial by military commission.

The Sons of Liberty, founded in part to get out the vote for Democratic candidates, also made initial plans to free thousands of Confederate soldiers held in Illinois and other states; the group may have also accepted money from Confederate agents in Canada. In August 1864, federal officials arrested Milligan and a handful of others, charging them with conspiracy, affording aid and comfort to the enemy, and other offenses. The Indianapolis military trials lasted from September to December 1864, partially amid the electoral campaign. The commission found Milligan guilty and sentenced him to death. The precise extent of Milligan’s involvement in the Sons of Liberty remains unclear.

Milligan and two others filed writs of habeas corpus with the federal court in Indianapolis, which certified the legal issues in the case to the Supreme Court. Milligan argued in part that military commissions had no power to try civilians like himself where the regular courts were open and functioning. The military trial meant that Milligan did not receive many constitutional protections afforded defendants tried by civilian courts, including the right to a jury of residents of Indiana and the right to be tried only for conduct that Congress had criminalized by law.

All nine justices agreed that the military commission that tried Milligan was unlawful, but they were deeply divided in their reasoning. The majority opinion, authored by Justice Davis, a longtime friend and political ally of Lincoln, reasoned broadly that neither Congress nor the president could authorize military trials of civilians, except in the actual theater of war where the regular courts were not functioning.

Chief Justice Chase, writing for the four-person concurrence, reasoned that Congress had not authorized the trial of Milligan; indeed, the Habeas Corpus Act of 1863 required that prisoners like Milligan had to be indicted by a grand jury or released. A grand jury had met just prior to Milligan’s arrest, but had failed to indict him. This settled the matter for Chase, who thought the majority erred by considering whether Congress would have the power to authorize military commissions if it attempted to do so. Chase also believed that the majority erred in how it answered this hypothetical question: he reasoned that Congress would have the power to establish such commissions.

Justice Davis’s famous opinion for the Court includes sweeping and often-cited language about the limits of government power during war. The opinion, however, met with immediate and vitriolic criticism from Republicans who charged that the Court’s reasoning would have lost the war for the Union and that Congress’s efforts at military reconstruction in the South would be fatally undermined. In 1868, the Court appeared ready to consider the constitutionality of military commissions authorized by reconstruction legislation in Ex parte McCardle. Congress, however, revoked the appellate jurisdiction of the Supreme Court over this and similar habeas appeals, and the Court honored the revocation.

Twentieth-century commentators sometimes applauded Milligan as a vitally important civil liberties opinion. Others argued that it has had little practical effect, noting that the Court issued it only after Confederate troops had surrendered and the war was over. An American citizen tried by a military commission during World War II relied in part on Milligan to support his petition for a writ of habeas corpus. The Court rejected the petition and distinguished Milligan on the grounds that the World War II defendant had actually joined the Nazis, while Milligan was not part of the enemy armed forces and was not subject to the laws of war. The president’s detention of ‘‘enemy combatants’’ in the United States following the September 11, 2001 terrorist attacks has once again raised fundamental questions about civil liberties and military authority, and has focused new attention on Milligan.

INGRID BRUNK WUERTH

References and Further Reading

• Fairman, Charles. History of the Supreme Court of the United States: Reconstruction and Reunion: 1864–1888. Vol. VI, Part I. New York: Macmillian Company, 1971.
• Klement, Frank L. ‘‘The Indianapolis Treason Trials and Ex parte Milligan.’’ In American Political Trials, edited by Michal R. Belknap. Westport, Conn.: Greenwood Press, 1981.
• Rehnquist, William H. All the Laws but One. New York: Alfred A. Knopf, 1998.
• Warren, Charles. The Supreme Court in United States History. Vol. 3, 1856–1918. Boston: Little, Brown, and Co., 1923.

Cases and Statutes Cited

• Ex parte McCardle, 74 U.S. 506 (1869)

See also Military Tribunals; 9/11 and the War on Terrorism