The grant of power to congress in the constitution to regulate commerce with foreign nations and among the several states, it is conceded, is paramount over all legislative powers which, in consequence of not having been granted to congress, are reserved to the states. It follows that any legislation of a state, although in pursuance of an acknowledged power reserved to it, which conflicts with the actual exercise of the power of congress over the subject of commerce, must give way before the supremacy of the national authority. As the regulation of commerce may consist in abstaining from prescribing positive rules for its conduct, it cannot always be said that the power to regulate is dormant because not affirmatively exercised. And when it is manifest that congress intends to leave that commerce which is subject to its jurisdiction, free and unfettered by any positive regulations, such intention would be contravened by state laws operating as regulations of commerce as much as though these had been expressly forbidden. In such cases, the existence of the power to regulate commerce in congress has been construed to be not only paramount but exclusive, so as to withdraw the subject as the basis of legislation altogether from the states. There are many cases, however, where the acknowledged powers of a state may be exerted and applied in such a manner as to affect foreign or interstate commerce without being intended to operate as commercial regulations. If their operation and application in such cases regulate such commerce, so as to conflict with the regulation of the same subject by congress, either as expressed in positive laws or implied from the absence of legislation, such legislation on the part of the state, to the extent of that conflict, must be regarded as annulled. To draw the line of interference between two fields of jurisdiction, and to define and declare the instances of unconstitutional encroachment, is a judicial question often of much difficulty, the solution of which, perhaps, is not to be found in any single and exact rule of decision. Some general lines of discrimination, however, have been drawn in varied and numerous decisions of this court. It has been uniformly held, for example, that the state cannot by legislation place burdens upon commerce with foreign nations or among the several states. 'But upon an examination of the cases in which they were rendered,' as was said in Sherlock v. Alling, 90 U. S. 99, 102, 'it will be found that the legislation adjudged in valid imposed a tax upon some instrument or subject of commerce, or exacted a license fee from parties engaged in commercial pursuits, or created an impediment to the free navigation of some public waters, or prescribed conditions in accordance with which commerce in particular articles or between particular places was required to be conducted. In all the cases, the legislation condemned operated directly upon commerce, either by way of tax upon its business, license upon its pursuit in particular channels, or conditions for carrying it on.' In that case it was held that a statute of Indiana, giving a right of action to the personal representatives of the deceased where his death was caused by the wrongful act or omission of another, was applicable to the case of a loss of life occasioned by a collision between steam-boats navigating the Ohio river, engaged in interstate commerce, and did not amount to a regulation of commerce in violation of the constitution of the United States. On this point the court said, (page 103:) 'General legislation of this kind, prescribing the liabilities or duties of citizens of a state, without distinction as to pursuit or calling, is not open to any valid objection because it may affect persons engaged in foreign or interstate commerce. Objection might, with equal propriety, be urged against legislation prescribing the form in which contracts shall be authenticated, or property descend or be distributed on the death of its owner, because applicable to the contracts or estates of persons engaged in such commerce. In conferring upon congress the regulation of commerce, it was never intended to cut the states off from legislating upon all subjects relating to the health, life, and safety of their citizens, though the legislation might indirectly affect the commerce of the country. Legislation, in a great variety of ways, may affect commerce and persons engaged in it, without constituting a regulation of it within the meaning of the c nstitution. * * * And it may be said, generally, that the legislation of a state, not directed against commerce or any of its regulations, but relating to the rights, duties, and liabilities of citizens, and only indirectly and remotely affecting the operations of commerce, is of obligatory force upon citizens within its territorial jurisdiction, whether on land or water, or engaged in commerce, foreign or interstate, or in any other pursuit.' In that case it was admitted, in the opinion of the court, that congress might legislate, under the power to regulate commerce, touching the liability of parties for marine torts resulting in the death of the persons injured, but that, in the absence of such legislation by congress, the statute of the state, giving such right of action, constituted no encroachment upon the commercial power of congress, although, as was also said, (page 103:) 'It is true that the commercial power conferred by the constitution is one without limitation. It authorizes legislation with respect to all the subjects of foreign and interstate commerce, the persons engaged in it, and the instruments by which it is carried on.'

The statute of Indiana, held to be valid in that case, was an addition to and an amendment of the general body of the law previously existing and inforce regulating the relative rights and duties of persons within the jurisdiction of the state, and operating upon them, even when engaged in the business of interstate commerce. This general system of law, subject to be modified by state legislation, whether consisting in that customary law which prevails as the common law of the land in each state, or as a code of positive provisions expressly enacted, is nevertheless the law of the state in which it is administered, and derives all its force and effect from the actual or presumed exercise of its legislative power. It does not emanate from the authority of the national government, nor flow from the exercise of any legislative powers conferred upon congress by the constitution of the United States, nor can it be implied as existing by force of any other legislative authority than that of the several states in which it is enforced. It has never been doubted but that this entire body and system of law, regulating in general the relative rights and duties of persons within the territorial jurisdiction of the state, without regard to their pursuits, is subject to change at the will of the legislature of each state, except as that will may be restrained by the constitution of the United States. It is to this law that persons within the scope of its operation look for the definition of their rights and for the redress of wrongs committed upon them. It is the source of all those relative obligations and duties enforceable by law, the observance of which the state undertakes to enforce as its public policy. And it was in contemplation of the continued existence of this separate system of law in each state that the constitution of the United States was framed and ordained with such legislative powers as are therein granted expressly or by reasonable implication.

It is among these laws of the states, therefore, that we find provisions concerning the rights and duties of common carriers of persons and merchandise, whether by land or by water, and the means authorized by which injuries resulting from the failure properly to perform their obligations may be either prevented or redressed. A carrier exercising his calling within a particular state, although engaged in the business of interstate commerce, is answerable, according to the laws of the state, for acts of nonfeasance or misfeasance committed within its limits. If he fail to deliver goods to the proper consignee at the right time or place, he is liable in an action for damages, under the laws of the state, in its courts; or if by negligence in transportation he inflicts injury upon the person of a passenger brought from another state, a right of action for the consequ nt damage is given by the local law. In neither case would it be a defense that the law giving the right to redress was void as being an unconstitutional regulation of commerce by the state. This, indeed, was the very point decided in Sherlock v. Alling, above cited. If it is competent for the state thus to administer justice according to its own laws for wrongs done and injuries suffered, when committed and inflicted by defendants while engaged in the business of interstate or foreign commerce, notwithstanding the power over those subjects conferred upon congress by the constitution, what is there to forbid the state, in the further exercise of the same jurisdiction, to prescribe the precautions and safeguards foreseen to be necessary and proper to prevent by anticipation those wrongs and injuries which, after they have been inflicted, it is admitted the state has power to redress and punish? If the state has power to secure to passengers conveyed by common carriers in their vehicles of transportation a right of action for the recovery of damages occasioned by the negligence of the carrier in not providing safe and suitable vehicles, or employes of sufficient skill and knowledge, or in not properly conducting and managing the act of transportation, why may not the state also impose, on behalf of the public, as additional means of prevention, penalties for the non-observance of these precautions? Why may it not define and declare what particular things shall be done and observed by such a carrier in order to insure the safety of the persons and things he carries, or of the persons and property of others liable to be affected by them? It is that law which defines who are or may be common carriers, and prescribes the means they shall adopt for the safety of that which is committed to their charge, and the rules according to which, under varying conditions, their conduct shall be measured and judged, which declares that the common carrier owes the duty of care, and what shall constitute that negligence for which he shall be responsible. But for the provisions on the subject found in the local law of each state, there would be no legal obligation on the part of the carrier, whether ex contractu or ex delicto, to those who employ him; or if the local law is held not to apply where the carrier is engaged in foreign or interstate commerce, then, in the absence of laws passed by congress or presumed to be adopted by it, there can be no rule of decision based upon rights and duties supposed to grow out of the relation of such carriers to the public or to individuals. In other words, if the law of the particular state does not govern that relation, and prescribe the rights and duties which it implies, then there is and can be no law that does, until congress expressly supplies it, or is held by implication to have supplied it, in cases within its jurisdiction over foreign and interstate commerce. The failure of congress to legislate can be construed only as an intention not to disturb what already exists, and is the mode by which it adopts, for cases within the scope of its power, the rule of the state law, which, until displaced, covers the subject.

There is no common law of the United States, in the sense of a national customary law, distinct from the common law of England, as adopted by the several states each for itself, applied as its local law, and subject to such alteration as may be provided by its own statutes. Wheaton v. Peters, 8 Pet. 591. A determination in a given case of what that law is may be different in a court of the United States from that which prevails in the judicial tribunals of a particular state. This arises from the circumstance that the courts of the United States, in cases within their jurisdiction, where they are called upon to administer the law of the state in which they sit or by which the transaction is governed, exercise an independent though concurrent jurisdiction, and are required to ascertain and eclare the law according to their own judgment. This is illustrated by the case of Railroad Co. v. Lockwood, 17 Wall. 357, where the common law prevailing in the state of New York, in reference to the liability of common carriers for negligence, received a different interpretation from that placed upon it by the judicial tribunals of the state; but the law as applied was none the less the law of that state. In cases, also, arising under the lex mercatoria, or law-merchant, by reason of its international character, this court has held itself less bound by the decisions of the state courts than in other cases. Swift v. Tyson, 16 Pet. 1; Carpenter v. Insurance Co., Id. 495; Oates Bank, 100 U. S. 239; Railroad Co. v Bank, 102 U. S. 14.

There is, however, one clear exception to the statement that there is no national common law. The interpretation of the constitution of the United States is necessarily influenced by the fact that its provisions are framed in the language of the English common law, and are to be read in the light of its history. The code of constitutional and statutory construction which, therefore, is gradually formed by the judgments of this court, in the application of the constitution and the laws and treaties made in pursuance thereof, has for its basis so much of the common law as may be implied in the subject, and constitutes a common law resting on national authority. Moore v. U. S., 91 U. S. 270. The statute of Alabama, the validity of which is drawn in question in this case, does not fall within this exception. It would, indeed, be competent for congress to legislate upon its subject-matter, and to prescribe the qualifications of locomotive engineers for employment by carriers engaged in foreign or interstate commerce. It has legislated upon a similar subject by prescribing the qualifications for pilots and engineers of steam-vessels engaged in the coasting trade and navigating the inland waters of the United States while engaged in commerce among the states, (Rev. St. tit. 52, §§ 4399-4500;) and such legislation undoubtedly is justified on the ground that it is incident to the power to regulate interstate commerce. In Sinnot v. Davenport, 22 How. 227, this court adjudged a law of the state of Alabama to be unconstitutional, so far as it applied to vessels engaged in interstate commerce, which prohibited any steam-boat from navigating any of the waters of the state without complying with certain prescribed conditions, inconsistent with the act of congress of February 17, 1793, in reference to the enrollment and licensing of vessels engaged in the coasting trade. In that case it was said, (page 243:) 'The whole commercial marine of the country is placed by the constitution under the regulation of congress, and all laws passed by that body in the regulation of navigation and trade, whether foreign or coastwise, is therefore but the exercise of an undisputed power. When, therefore, an act of the legislature of a state prescribes a regulation of the subject repugnant to and inconsistent with the regulation of congress, the state law must give way, and this without regard to the source of power whence the state legislature derived its enactment.' The power might with equal authority be exercised in prescribing the qualifications for locomotive engineers employed by railroad companies engaged in the transportation of passengers and goods among the states, and in that case would supersede any conflicting provisions on the same subject made by local authority.

But the provisions on the subject contained in the statute of Alabama under consideration are not regulations of interstate commerce. It is a misnomer to call them such. Considered in themselves, they are parts of that body of the local law which, as we have already seen, properly governs the relation between carriers of passengers and merchandise, and the public who employ them, which are not displaced until they come in conflict with express enactments of congress in the exercise of its power over commerce, and which, until so displaced, according to the evident intention of congress, remain as the law governing carriers, in the discharge of their obligations, whether engaged in the purely internal commerce of the state or in commerce among the states. No objection to the statute, as an impediment to the free transaction of commerce among the states, can be found in any of its special provisions. It requires that every locomotive engineer shall have a license, but it does not limit the number of persons who may be licensed, nor prescribe any arbitrary conditions to the grant. The fee of five dollars to be paid by an applicant for his examination is not a provision for raising revenue, but it is no more than an equivalent for the service rendered, and cannot be considered in the light of a tax or burden upon transportation. The applicant is required, before obtaining his license, to satisfy a board of examiners in reference to his knowledge of practical mechanics, his skill in operating a locomotive engine, and his general competency as an engineer, and the board, before issuing the license, is required to inquire into his character and habits, and to withhold the license if he be found to be reckless or intemperate. Certainly it is the duty of every carrier, whether engaged in the domestic commerce of the state or in interstate commerce, to provide and furnish itself with locomotive engineers of this precise description; competent and well qualified, skilled and sober; and if, by reason of carelessness in the selection of an engineer not so qualified, injury or loss are caused, the carrier no matter in what business engaged, is responsible according to the local law admitted to govern in such cases, in the absence of congressional legislation.

The statute in question further provides that any engineer licensed under the act shall forfeit his license if at any time found guilty by the board of examiners of an act of recklessness, carelessness, or negligence while running an engine, by which damage to person or property is done, or who shall immediately preceding or during the time he is engaged in running an engine be in a state of intoxication; and the board are authorized to revoke and cancel the license whenever they shall be satisfied of the unfitness or incompetency of the engineer by reason of any act or habit unknown at the time of his examination, or acquired or formed subsequent to it. The eighth section of the act declares that any engineer violating its provisions shall be guilty of a misdemeanor, and upon conviction inflicts upon him the punishment of a fine not less than $50 nor more than $500, and also that he may be sentenced to hard labor for the county for not more than six months. If a locomotive engineer, running an engine, as was the petitioner in this case, in the business of transporting passengers and goods between Alabama and other states should, while in that state, by mere negligence and recklessness in operating his engine, cause the death of one or more passengers carried, he might certainly be held to answer to the criminal laws of the state if they declare the offense in such a case to be manslaughter. The power to punish for the offense after it is committed certainly includes the power to provide penalties directed, as are those in the statute in question, against those acts of omission which, if performed, would prevent the commission of the larger offense. It is to be remembered that railroads are not natural highways of trade and commerce. They are artificial creations; they are constructed within the territoral limits of a state, and by the authority of its laws, and ordinarily by means of corporations exercising their franchises by limited grants from the state. The places where they may be located, and the plans according to which they must be constructed, are prescribed by the legislation of the state. Their operation requir § the use of instruments and agencies attended with special risks and dangers, the proper management of which involves peculiar knowledge, training, skill, and care. The safety of the public in person and property demands the use of specific guards and precautions. The width of the gauge, the character of the grades, the mode of crossing streams by culverts and bridges, the kind of cuts and tunnels, the mode of crossing other highways, the placing of watchmen and signals at points of special danger, the rate of speed at stations and through villages, towns, and cities, are all matters naturally and peculiarly within the provisions of that law from the authority of which these modern highways of commerce derive their existence. The rules prescribed for their construction and for their management and operation, designed to protect persons and property, otherwise endangered by their use, are strictly within the limits of the local law. They are not per se regulations of commerce; it is only when they operate as such in the circumstances of their application, and conflict with the expressed or presumed will of congress exerted on the same subject, that they can be required to give way to the supreme authority of the constitution.

In conclusion, we find, therefore—First, that the statute of Alabama, the validity of which is under consideration, is not, considered in its own nature, a regulation of interstate commerce, even when applied as in the case under consideration; secondly, that it is properly an act of legislation within the scope of the admitted power reserved to the states to regulate the relative rights and duties of persons being and acting within its territorial jurisdiction, intended to operate so as secure for the public safety of person and property; and, thirdly, that, so far as it affects transactions of commerce among the states, it does so only indirectly, incidentally, and remotely, and not so as to burden or impede them, and, in the particulars in which it touches those transactions at all, it is not in conflict with any express enactment of congress on the subject, nor contrary to any intention of congress to be presumed from its silence. For these reasons, we hold this statute, so far as it is alleged to contravene the constitution of the United States, to be a valid law. The judgment of the supreme court of Alabama is therefore affirmed.

BRADLEY, J., dissented.