Ex Parte Milligan was after the war.
There was enough question about the issue to give President Lincoln the benefit of the doubt in 1861.
Lincoln did suspend the writ. It is a fact.
The question is whether it was lawful.
Contemporaneously, CJ Taney issued a Writ of Habeas Corpus. The Executive refused to comply.
As a matter of law (not right or wrong), can the Executive interpretation of the law overrule the Judiciary interpretation of the law?
While Ex Parte Milligan was decided by the Supreme Court after the war, it was ruling on events that occurred during the war.
From Ex Parte Milligan
The crimes with which Milligan was charged were of the gravest character, and the petition and exhibits in the record, which must here be taken as true, admit his guilt. But whatever his desert of punishment may be, it is more important to the country and to every citizen that he should not be punished under an illegal sentence, sanctioned by this court of last resort, than that he should be punished at all. The laws which protect the liberties of the whole people must not be violated or set aside in order to inflict, even upon the guilty, unauthorized though merited justice.
The trial and sentence of Milligan were by military commission convened in Indiana during the fall of 1864. The action of the commission had been under consideration by President Lincoln for some time, when he himself became the victim of an abhorred conspiracy. It was approved by his successor in May, 1865, and the sentence was ordered to be carried into execution.
The proceedings, therefore, had the fullest sanction of the executive department of the government. [71 U.S. 2, 133] This sanction requires the most respectful and the most careful consideration of this court. The sentence which it supports must not be set aside except upon the clearest conviction that it cannot be reconciled with the Constitution and the constitutional legislation of Congress.
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The first question, therefore-Ought the writ to issue?-must be answered in the affirmative. [71 U.S. 2, 135] And it is equally clear that he was entitled to the discharge prayed for.
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An affirmative answer must, therefore, be given to the second question, namely: Ought Milligan to be discharged according to the prayer of the petition?
That the third question, namely: Had the military commission in Indiana, under the facts stated, jurisdiction to try and sentence Milligan? must be answered negatively is an unavoidable inference from affirmative answers to the other two. [71 U.S. 2, 136] The military commission could not have jurisdiction to try and sentence Milligan, if he could not be detained in prison under his original arrest or under sentence, after the close of a session of the grand jury without indictment or other proceeding against him.
Indeed, the act seems to have been framed on purpose to secure the trial of all offences of citizens by civil tribunals, in states where these tribunals were not interrupted in the regular exercise of their functions.
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We agree in the proposition that no department of the [71 U.S. 2, 137] government of the United States-neither President, nor Congress, nor the Courts-possesses any power not given by the Constitution.
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It is not denied that the power to make rules for the government of the army and navy is a power to provide for trial and punishment by military courts without a jury. It has been so understood and exercised from the adoption of the Constitution to the present time.
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We by no means assert that Congress can establish and apply the laws of war where no war has been declared or exists.
Where peace exists the laws of peace must prevail. What we do maintain is, that when the nation is involved in war, and some portions of the country are invaded, and all are exposed to invasion, it is within the power of Congress to determine in what states or district such great and imminent public danger exists as justifies the authorization of military tribunals for the trial of crimes and offences against the discipline or security of the army or against the public safety.
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We cannot doubt that, in such a time of public danger, Congress had power, under the Constitution, to provide for the organization of a military commission, and for trial by that commission of persons engaged in this conspiracy. The fact that the Federal courts were open was regarded by Congress as a sufficient reason for not exercising the power; but that fact could not deprive Congress of the right to exercise it. Those courts might be open and undisturbed in the execution [71 U.S. 2, 141] of their functions, and yet wholly incompetent to avert threatened danger, or to punish, with adequate promptitude and certainty, the guilty conspirators.
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We have confined ourselves to the question of power. It was for Congress to determine the question of expediency. And Congress did determine it. That body did not see fit to authorize trials by military commission in Indiana, but by the strongest implication prohibited them.
[bold-face added]
In President Lincoln's day, each branch was viewed as having the power to interpret the Constitution for itself.
Lincoln addressed this in his first inaugural address:
"I do not forget the position assumed by some that constitutional questions are to be decided by the Supreme Court, nor do I deny that such decisions must be binding in any case upon the parties to a suit as to the object of that suit, while they are also entitled to very high respect and consideration in all parallel cases by all other departments of the Government. And while it is obviously possible that such decision may be erroneous in any given case, still the evil effect following it, being limited to that particular case, with the chance that it may be overruled and never become a precedent for other cases, can better be borne than could the evils of a different practice. At the same time, the candid citizen must confess that if the policy of the Government upon vital questions affecting the whole people is to be irrevocably fixed by decisions of the Supreme Court, the instant they are made in ordinary litigation between parties in personal actions the people will have ceased to be their own rulers, having to that extent practically resigned their Government into the hands of that eminent tribunal."
You don't want to fall into the very common trap of judging historical people by modern day standards.
Walt
"The decision was announced April 3, 1866. The court unanimously ruled that military commissions had no jurisdiction in a case such as Milligan's, and it ordered his sentence set aside. He was to be released. The justices took time and care in writing their opinions. The full ruling, finished in July 1866, was written by Justice David Davis, a Lincoln appointee and a longtime friend of the slain president.
"During the late wicked Rebellion," he wrote, "the temper of the times did not allow that calmness in deliberation and discussion so necessary to a correct conclusion of a purely judicial question. Then considerations of safety were mingled with the exercise of power; and feelings and interest prevailed which are happily terminated. Now that the public safety is assured, this question, as well as others, can be discussed and decided without passion, or the admixture of any element not required to form a legal judgment."
And he ruled that the administration's course had been wrong after all. "Martial law cannot arise from a threatened invasion," but only from a real one. "Martial rule can never exist where the courts are open, and in the proper and unobstructed exercise of their jurisdiction." This had clearly been the case in Indiana in 1864, as even the government's lawyers admitted. "Wicked men, ambitious of power, with hatred of liberty and contempt of law, may fill the place once occupied by Washington and Lincoln; and if this right is conceded, and the calamities of war again befall us, the dangers to human liberty are frightful to contemplate."
Milligan was set free, then promptly seized by civil authorities, but they never pressed charges against him and ultimately released him. He filed suit to collect damages, but the statute of limitations had expired, and the jury awarded him a mere $5."
The court went out of its way to praise President Lincoln.
When Milligan was arrested, there was no precedent to say he might not be arrested. He would have hanged except for Lincoln
In 1942, the Court denied Habeas Corpus petetitions filed on behalf of German agents captured in New York and Florida. President Roosevelt ordred that six, as I recall, be executed at noon the next day. By 1:30 thet were all dead. Clearly under Milligan New York and Florida were not theaters of war.
Neo-reb apologists hate it when that the president takes reasonable action to defend the country.
Walt