PREFACE IN the preparation of such a work as this an author is under the temptation unduly to dwell on matters of contemporary interest, and thus to lose the sense of due proportion. In taking up and prosecuting the work, it was my purpose and it has been my effort to make a clear, coherent, and comprehensive presentation of the subject, strictly within its scope, convenient for the practicing lawyer and the legislator, while useful also as a text-book for the student. The construction, scope, and effect of statutes passed in exercise of the power of Congress to regulate commerce have not been discussed unless it seemed that a fundamental question was involved in the particular consideration. This presentation is mainly based upon a careful examination of all the cases on the subject decided by the Supreme Court of the United States. On the moot question of the existence and nature of a federal police power I have endeavored to find and state a general principle. The working out of the principle has relation chiefly to the question of the power to regulate commerce as including the power to prohibit, and the relation of this power to a consideration of the power of Congress indirectly to regulate manufacture by denying the facilities of interstate transportation to commodities not manufactured under conditions prescribed by Congress. In separate parts of the work these two topics are 166929 treated, and the principle suggested can perhaps be understood only by referring to both parts. No other department of constitutional law furnishes such an opportunity to acquire a knowledge of the respective powers of the federal and State governments as does a study of this subject. The enlightenment acquired reveals the existence of an exclusive authority of the States as to all matters concerning their domestic commerce, and a power in the States concurrent with, but subordinate to, that of Congress respecting many matters affecting the instrumentalities of interstate and foreign commerce. We hear much said about enlarging the powers of the federal government by judicial construction. Whatever else the suggestion may allude to, it cannot refer to the power of Congress to regulate the instrumentalities of interstate commerce. It is impossible to give any attention to the subject without being impressed with the wide powers possessed by the States over the instrumentalities of commerce, even in matters having relation to and affecting their interstate and foreign business. The question of the expediency of the adoption, whether by the national government or by the States, of regulations which may be said to be within the concurrent powers of the federal and State governments, but inoperative as to the State enactment when Congress has legislated on the particular subject, must in many instances be determined by the sufficiency of the action of the States to meet the local requirements. The failure of the States to adopt regulations to meet a supposed need, either by indifference to the wrong or delinquency or by such an exercise of the power that, on account of [iv] the absolute requirements imposed, a regulation cannot pass the supreme test of reasonableness, results in agitation for federal regulation of matters concerning which the power of Congress is undoubted. There would be no need to invoke the exercise of the federal power in such cases if States adopted reasonable regulations to satisfy local requirements or opinion. This topic may be illustrated by comparing the attempt of the State of Texas to meet the car shortage problem, and the laws of several of the States prohibiting the running of freight trains on Sunday. In the case respecting the Texas statute, the court seemed careful to avoid saying that the subject-matter of the statute is not a proper matter for the exercise of the State police power. Indeed, it was strongly intimated that such a regulation is within the same class of subjects as those regarding the speed of trains, the length and frequency of stops, the heating, lighting, and ventilation of passenger cars, and the furnishing of food and water to cattle and live stock. It was, however, the failure of the statute to make allowance for contingencies which good management and a desire to fulfil all legal requirements cannot provide for, that constrained the court to declare the statute to be unreasonable and invalid. If the State laws prohibiting the transportation of freight on Sundays. required that freight trains should stop at twelveo'clock on Saturday night, it cannot be supposed that they would be sustained as to trains carrying interstate and foreign freight. But by permitting trains running on Saturday night to run through to destination or to reach, before eight or nine o'clock on Sunday morning, a convenient place to wait |