There is, then, strictly speaking, no such thing in American law as a declaration of martial law whereby military is substituted for civil law. So-called declarations of martial law are, indeed, often made, but the legal effect of these goes no further than to warn citizens that the military powers have been called upon by the executive to assist him in the maintenance of law and order, and that, while the emergency lasts, they must, upon pain of arrest and punishment, not commit any acts which will in any way render more difficult the restoration of order and the enforcement of law. Some of the authorities stating substantially this doctrine are quoted in the footnote below.7

7 "The term martial law refers to the exceptional measures adopted whether by the military or the civil authorities, in times of war or of domestic disturbance, for the preservation of order and the maintenance of the public authority. To the operation of martial law all the inhabitants of the country or of the disturbed district, aliens as well as citizens, are subject." Moore, Int. Law Digest, II, 186. As to the subjection of aliens to Martial Law, see Moore, II, 196.

In the cases of the Bristol Riots in 1831-1832 (S. T. U. S. IIIl, 2-56), the opinion reads: "A soldier for the purpose of establishing civil order is only a citizen armed in a particular manner. He cannot because he is a soldier excuse himself if without necessity he takes human life. The duty of magistrates and peace officers to summon or to abstain from summoning the assistance of the military depends in like manner on the necessities of the case. . . . The whole action of the military when called in ought, from first to last, to be based on the principle of doing, and doing without fear, that which is absolutely necessary to prevent serious crime, and of exercising all care and skill with regard to what is done. No set of rules exists which the case of the police power, by necessity, actual or reasonably presumed. During times of disorder, such as lead to a call upon the military forces for assistance, necessity naturally demands the commission of acts which in more tranquil times are not demanded, and thus in fact, those in authority may control the individual and his property in ways which they could not legally do at other times, but the principle still holds good that necessity, and necessity alone, will justify an infringement upon private rights of person and property.

During the time that the military forces are employed for the enforcement of law, that is to say, when so-called martial law is in force, no new powers are given to the executive, no extension of arbitrary authority is recognized, no civil rights of the individual are suspended.8 The relations of the citizen to his State are unchanged. Whatever interference there may be with his personal freedom or property rights must be justified, as in governs every instance or defines beforehand every contingency which may arise. . . . The question whether, on any occasion, the moment has come for firing upon a mob of rioters, depends, as we have said, on the necessities of the case. ... An order from the magistrate who is present is required by military regulations, and wisdom and discretion are entirely in favor of the observance of such a practice. But the order of the magistrate has at law no legal effect. Its presence does not justify the firing if the magistrate is wrong. Its absence does not excuse the officer from declining to fire when the necessity exists. With the above doctrines of English law the Riot Act does not interfere. Its effect is only to make the failure of a crowd to disperse for a whole hour after the proclamation has been read a felony; and on this ground to afford statutory justification for dispersing a felonious assemblage, even at the risk of taking life."

In Ela v. Smith (5 Gray [Mass.], 121) the court say: "While thus recognizing the authority of the civil officers to call out and use an armed force to aid in suppressing a riot or tumult actually existing, or preventing one which is threatened, it must be borne in mind that no power is conferred on the troops, when so assembled, to act independently of the civil authority. . . . They are to act as an armed police only, subject to the absolute and exclusive control and direction of the magistrates and other civil officers designated in the statute, as to the specific duty or service which they are to perform. Nor can the magistrate delegate his authority to the military force which he summons to his aid; or vest in the military authorities any discretionary power to take any steps or do any act to prevent or suppress a mob or riot. They must perform only such service, and render such aid, as is required by the civil officers. ... It does not follow from this, however, that the military force is to be taken wholly out of the control of the proper officers. They are to direct its movements in the execution of the orders given by the civil officers, and to manage the details in which a specific service or duty is to be performed. But the service or duty must be first prescribed and designated by the civil authority."

8 The writ of habeas corpus may have been suspended. Of this we shall speak presently. But this suspension does not give any additional arbitrary authority to either the civil or military authorities, - it does not operate to legalize any act of theirs that otherwise would have been illegal. The only effect of the suspension of the writ is to prevent, for the time being, a judicial examination of the legality of the detention of the individual.