Mr, Justice CURTIS
delivered the opinion of the court.
These cases are brought here by writs of error to the Supreme Court of the Commonwealth of Pennsylvania.
They are actions to recover half-pilotage fees under the 29th section of the act of the Legislature of Pennsylvania, passed on the second day of March, 1803. The plaintiff in error alleges that the highest court of the State has decided against a right claimed by him under the Constitution -of the United States. That right is to be exempted from the payment of the sums of money demanded, pursuant to the State law above referred to, because that law contravenes several provisions of the Constitution of the United States.
The particular section of the State law drawn in question is as follows:
“ That every ship or vessel arriving from or bound to any foreign port or place, and every ship or vessel of the burden of seventy-five tons or more, sailing from or bound to any .port not within the river Delaware, shall be obliged to receive a pilot. And it shall be the duty of the master of every such ship or vessel, within thirty-six hours next after the arrival of such ship - or vessel at the city of Philadelphia, to make report to the master-warden of the name of such ship or vessel, her draught of water, and the name of the pilot who shall, have conducted her to the port. And when any such vessel shall be outward-bound, the master of such vessel shall make known to the wardens the name of such vessel, and .of the pilot who is to conduct her to the capes, and her draught of water at that time., And it shall be the duty of the wardens to enter eveiy such vessel in a book to be by them kept for that purpose, without fee or reward. And if the master of any ship or vessel shall neglect to .make such report, he shall forfeit and pay the sum of sixty dpllars. And if the master of any such ship or vessel shall refuse or neglect to take a pilot, the master, owner or consignee of such vessel shall forfeit and pay to the warden aforesaid, a. sum equal, to the half-pilotage of súch ship or vessel, to the use of the Society for the Relief, &c., to be recovered as pilotage in the manner herein-, after directed: Provided always, that where it shall appear to the warden that, in case of an inward-bound vessel, a pilot did [312]*312not offer before she had reached Reedy Island; or, in case of an outward-bound vessel, that a pilot could not be obtained for twenty-four hours after such vessel was ready to depart, the penalty aforesaid, for not having a pilot, shall not be incurred.” It constitutes one. section of “ An act to establish'a Board of Wardens, for the port of Philadelphia, and for the regulation of Pilots and Pilotages, &c.,” and the scope of the act is in conformity with the- title to regulate the whole subject of the pilot-age of that port.
Í- We'think this particular regulation concerning half-pilotage fees, is an appropriate part of a general system of regulations of this subject. Testing it by the practice of commercial States ,and countries legislating on this subject, we find it has usually been deemed necessary'to make similar provisions. Numerous laws of this kind are cited in the learned argument of the counsel for the defendant in error; and their fitness, as a part of a system of pilotage, in many places, may be inferred from their existence in so many different States and countries. Like other laws they are framed to meet the most usual cases, quce frequentius accidwit; they rest upon the propriety of securing lives and property exposed to the perils of a dangerous navigation, by taking, on board a person peculiarly skilled to encounter or avoid them; upon the policy of discouraging the commanders of vessels from refusing tor receive such persons on board at the proper times and places; and upon the' expediency, and even intrinsic justice, of not suffering those who have incurred labor, and expense, and danger, to place themselves in a position to render important service generally necessary, to go unrewarded, because the "master of a particular vessel either rashly refuses' their proffered assistance, or, contrary to the general experience, does not need it. There are many cases, in which an offer to perform, accompanied by present ability to perform, is deemed by law equivalent to performance. The laws of commercial States and countries have made an offer of pilotage-service one offthose cases; and we cannot pronounce a law which does this, to-be so far removed from the usual and fit scope of laws for the regulation of pilots and pilotage, as to be deemed, for this cause, a covert attempt to legislate upon another subject under the appearance of legislating on this one.
- It is urged that the second section of the act of the Legislature of Pennsylvania, of the 11th of June, 183á, proves that the State had other objects in view than the regulation of pilotage. That section is as follows:
“ And be it further enacted, by the authority aforesaid, that from and after the first day of July next, no health-fee or halfpilotage shall be charged on any vessel engaged in the Pennsylvania coal trade-”.
[313]*313It must be remembered, that the fair objects' of a law imposing half-pilotage when a pilot is not received, may be secured, and at the same time some classes of vessels exempted from such charge. Thus the very section of the act of 1803, now under consideration, does not apply to coasting vessels of less burden than seventy-five tons, nor fo those bound to, or sailing from, a port in the river Delaware. The purpose of the law being to cause masters of such vessels as generally need a pilot, to employ one, and to secure to the pilots a fair remuneration for cruising in search of vessels, or waiting for employment in port,, there is an obvious propriety in having reference to the number, size, and nature of employment of vessels frequenting the port; and it will be found, by an examination of the different systems of these regulations, which have from time to time been made in this and other countries, that the legislative discretion has been constantly exercised in making discriminations, founded on differences both in the character of the trade, and the tonnage of vessels engaged therein. .
We do not perceive any thing in the nature or extent of this particular , discrimination in favor of vessels engaged in the coal trade, which would enable us to declare it to be other than a fair exercise of legislative' discretion, acting upon the subject of the regulation of the pilotage of this port of Philadelphia, with a view to operate upon the masters of those vessels, who, as a general rule, ought to take a pilot, and' with the further view of relieving from the charge of half-pilotage, such vessels as from their size, or the nature of their employment, should be exempted from contributing to the support of pilots, except .so far as they actually receive their services. In our judgment, though this law of 1832 has undoubtedly modified the 29th section of the act of 1803, and both are to be taken together as giving the rule on this subject of half-pilotage, yet this change in the ■rule has not changed the nature of- the law, nor deprived it of .the character and attributes of a law for the regulation of pilotage.
Nor do we consider- that the appropriation of the sums received under this section of the act, to the use of the society for the relief of distressed and decayed pilots, their widows and children, has any legitimate tendency to impress on it the character of a revenue law. Whether these sums .shall go directly to the use of tfie individual pilots by whom the service is tendered, or shall form a common fund, to be administered by trustees for the benefit of such pilots and their families as may stand in peculiar need of it, is a matter resting in legislative discretion, in the proper exercise of which the pilots alone are interested.
For these reasons, we cannot yield our assent to the argument, that this provision of law is in conflict with the second [314]*314and third clauses of the tenth section of the first article of the Constitution, which prohibit a State, without the assent of Congress, 'from laying any imposts or duties, on imports or exports, or tonnage. This provision of the Constitution was intended to operate, upon subjects actually existing and well understood whén the Constitution was formed. Imposts and duties on imports, exports, and tonnage were then known to the commerce of a civilized world to be as distinct from fees and charges for pilotage, and from the penalties by which commercial States enforced their pilot-laws, as they were from 'charges for wharfage, or towage,, or any other local port-charges for services rendered-to vessels .or cargoes; and to declare that such pilot-fees or .'penalties, are embraced within the words imposts or duties on imports,- exports, or tonnage, would be to confound things essentially different, and which must have been known to be actually.different by those who used this language. It cannot be denied that-a tonnage-duty, or an impost on imports or exports, may be levied under the name of pilot-dues or penalties ; and: certainly it is the thing, and not the name, which is to b¿ considered. But,, having previously stated that, in this instance, the law complained of does not-pass the appropriate line which limits' laws for'.the regulation -of pilots and pilotage, the suggestion; that this law'levies a duty-on tonnage or on imports dr exports, is not admissible; and, if so, it also follows, that this law is not repugnant to the first clause of the eighth section of the first article of the Constitution, which declares that all duties, imposts, and excises shall be uniform throughout the United States; for, if it is not to be deemed a law levying a duty, impost, or excise, the want' of uniformity throughout the United States is not objectionable. Indeed the necessity of conforming regulations of pilotage to the local peculiarities of each port, and the consequent impossibility of having its charges uniform throughout the United States, would be sufficient of itself to prove that they could not have been intended to be embraced Within this clause of the Constitution; for it cannot be supposed uniformity was required, when it must have been known to be impracticable.
It is further objected, that this law is repugnant to the fifth clause of the ninth section of the first article of the Constitution, viz. — “No preference shall be given by any regulation of commerce or revenue, to the ports of one State over those of another; nor shall vessels, to or from one State, be obliged to enter, clear, or pay duties in another.”
But, as already stated, pilotage-fees are not duties within .the meaning of the Constitution; and, certainly, Pennsylvania does not give a preference to the port of Philadelphia, by requiring [315]*315the masters, owners, or consignees of vessels, sailing to or from that port, to pay the charges imposed by the twenty-ninth section of the act of 1803. It is an objection to, and not a ground of preference of a port, that a charge of this kind must be borne by vessels entering it; and, accordingly, the interests of the port require, and generally produce, such alleviations of these charges as its growing commerce from time'to time renders consistent with the general policy of the pilot-laws. This State, by its act of the 24th of March, 1851, ,has essentially modified the law of 1803, and further exempted many vessels from the charge now in question. Similar changes may be observed in the Jaws of New York, Massachusetts, and other commercial States, and they undoubtedly spring from the conviction that burdens of this land, instead of operating to give a "preference to a port, tend to checlt its commerce, and that sound policy requirés them to be lessened and removed .as early as the necessities of the system will allow.
In addition to what has been said respecting each of these constitutional objections to this law, it may be observed, that similar laws have existed and been practised on in the States since the' adoption of the federal Constitution; that, by the act of the 7th of August, 1789, (1 Stat. at Large, 54,) Congress declared that all pilots in the bays, inlets, rivers, harbors, and ports of the United States, shall continue to be regulated in conformity with the existing laws of the States, &c.; and that this contemporaneous construction of the Constitution since acted on with such uniformity in a matter of much public interest and importance, is entitled to great weiglit, in determining whether such a law is repugnant to the Constitution, as levying a duty-not uniform throughout the United States, or, as giving a preference to the ports of one State over those of another, or, as obliging vessels to or from one State to enter, clear, or pay duties in anotlier. Stuart v. Laird, 1 Cranch, 299; Martin v. Hunter, 1 Wheat. 304; Cohens v. The Commonwealth of Virginia, 6 Wheat. 264; Prigg v. The Commonwealth of Pennsylvania, 16 Pet. 621.
The opinion of the court is, that the law now in question is not repugnant to either of the above-mentioned clauses of the Constitution.
It remains to consider. the objection, that it is repugnant to the third clause of the eighth section of the first article. “ Tire Congress shall have power to regulate commerce with foreign nations and among the several States, and with the Indian tribes.”
That the power to regulate commerce includes the regulation of navigation, we consider settled. And when we look, to the [316]*316nature of the service performed, by pilots, to the relations which that service and its compensations bear to navigation between the several States, and between the ports of the United States and foreign countries, we are brought to the conclusion, that the regulation of the qualifications of pilots, of the modes and times of offering and rendering their services, of the responsibilities which shall rest upon' them, of the powers they shall possess, of the compensation they may demand, and of the. penalties by which' their rights and duties- may be enforced, do constitute regulations of navigation, and consequently of commerce, within the just meaning of this clause of the Constitution.
The power to regulate navigation is the power to prescribe rules in conformity with which navigation must be carried on. It extends to the persons who conduct it, as well as to the instruments used. Accordingly, the first Congress assembled under the Constitution passed laws, requiring the masters of ships and vessels of the United States to be citizens of the United States, and established many rules for the government and regulation of officers and seamen. 1 Stat. at Large, 55, 131. These have been from time to time added to and changed, and we are not aware that their validity has been questioned.
New, a pilot, so far as respects the navigation of the vessel in that part of the voyage which is his pilotage-ground, is the temporary master charged' with ■ the safety of the vessel and cargo, and of the lives of those on board, and intrusted with the command of the crew.- He is not only one of the persons engaged in navigation, but he occupies a most important and responsible place among those thus engaged. And if Congress has power to regulate the seamen who assist the pilot in the management of the vessel, a power never denied, we can perceive no valid reason why the pilot should be beyond the reach of the same power. It is true that, according to the usages of modem commercé on the ocean, the pilot is on board only during a part of the voyage between ports of different States, or between .ports of the United States and foreign countries; but if he is on board for such a purpose and during so much of the voyage as to be engaged in' navigation, the power to regulate navigation extends to him while thus engaged, as clearly as it would if h.e were to remain on board throughout the whole passage, from port to port. For it is a power which extends to every part of the voyage, and may regulate those who conduct or assist in conducting navigation in one part of a voyage as much as in another part, or during the whole voyage.
Nor should it be lqst sight of, that this subject of the regulation of pilots and pilotage has am intimate connection with, and an important relation to. the general subject of commerce with [317]*317foreign nations and among the several States, over which it was one main object of the Constitution to create a national control. Conflicts between the laws of neighboring States, and discriminations favorable or adverse to commerce with particular foreign nations, might be created by State laws regulating pilotage, deeply affecting that equality of commercial rights, and that freedom from State interference, which those who formed the Constitution were so anxious to secure, and which the experience of more than half a century has taught us to value so highly. The apprehension of this danger is not speculative merely. For, in 1837, Congress actually interposed to relieve the commerce of the country from serious embarrassment, arising from the laws of different States, situate upon waters which are the boundary between them. This was done by an enactment of the 2d of March, 1837, in the following words:
. “ Be it enacted, that it shall and may be lawful for the master or- commander of any vessel coming into or going out of any port situate upon waters which are the boundary between two States, to employ any pilot. duly licensed or authorized, by the laws of either of the States bounded .on the said waters, to pilot said vessel to or from said port, any law, usage, or custom, to the contrary, notwithstanding.”
The act of 1789, (1 Stat. at Large, 54,) already referred to, contains a clear legislative exposition of the Constitution by the first Congress,.to the effect that the power to regulate pilots •was conferred on Congress by the Constitution; as does also the act of March the 2d, 1837, the terms of which have just been given. The weight to be allowed to this contemporaneous construction, and the practice of Congress under it, has, in- another connection, been adverted to. And a majority of the court are of opinion, that a regulation of pilots is a regulation of commerce, within the grant to Congress of the commercial .power,' contained in the third clause of the eighth section of. the first article of the Constitution.
It becomes necessary, therefore, to consider whether this law of Pennsylvania, being a regulation of commerce, is valid.
’ The act of Congress of the 7th of August, 1789, sect. 4, is as follows:
“ That all pilots in the bays, inlets, rivers, harbors, and ports of the United States shall continue to be regulated in conformity with the existing laws of the States, respectively, wherein such pilots may be, or with such laws as the States may re- ■ spectively hereafter enact for the purpose, until further legislative provision shall be made by Congress.”
■ If the law of Pennsylvania, now in question, had been in existence at the date of this act of Congress, we might hold it to [318]*318have been adopted by Congress, and thus made a law of the United States, and so valid. Because this act does, in effect, give the force of an act of Congress, to the then existing State laws on this subject, so long as they should continue unrepealed by the State which enacted them.
But the law on which these actions are founded'was not enacted till 1803. What effect then can be attributed to so much of the act of 1789, as declares, that pilots shall continue to be regulated in conformity, “ with such laws as the States may respectively hereafter enact for the purpose, until further legislative provision shall be made by Congress ” ?
If the States were divested of the power to legislate on this subject by the grant of the. commercial power to Congress, it is plain this act could not confer upon them power thus to legislate. If the Constitution excluded the States from making any law regulating commerce, certainly Congress cannot regrant, or in any manner reconvey to the States that power. And yet this act of 1789 gives its sanction only to laws enacted by the States. This necessarily implies a constitutional power to legislate; for only a rule created by the sovereign power of a State acting in its, legislative capacity, can be deemed a law, enacted by a State; and if the State has so limited its sovereign power that it no longer extends to a particular subject, manifestly it cannot, in any proper sense, be said to enact laws thereon. Entertaining these views we are brought directly and unavoidably to the consideration of the question, whether the grant of the commercial power to Congress, did per se deprive the States of all power to regulate pilots.. This question has never been decided by this court, nor, in our judgment, has any case depending upon all the considerations which must govern this one, come before this court. The grant of commercial power to Congress does not contain any terms which expressly exclude the States from exercising an authority over its subject-matter. If they are excluded it must be because the nature of the power, thus granted to Congress,- requires that a similar authority should not exist in the States. If it were conceded on the one side, that the nature of this power, .like that to legislate for the District of Columbia, is absolutely and totally repugnant to the existence of similar power in the States, probably no one would deny that the grant of the power to Congress, as effectually and perfectly excludes the States from all future legislation on the subject, as if express words had been used to exclude’them, And on the other hand, if it were admitted that the existence of this power in Congress, like the power of taxation, is compatible with the existence of a similar-power in the States, then it would be in conformity with the contemporary.exposition of the Constitution, (Federalist, No. 32,) [319]*319and with the judicial construction, given from time to timb by this court, after the most deliberate consideration., to hold that the mere grant of such a power to Congress, did not imply a prohibition on the States to exercise the same power; that it is not the mere existence of such a power, but its exercise by Congress, which may be incompatible with the exercise of the same power by the States, and that the- States may legislate- in the absence of congressional regulations. Sturges v. Crowninshield, 4 Wheat. 193; Moore v. Houston, 5 Wheat. 1; Wilson v. Blackbird Creek Co. 2 Peters, 251.
The diversities of opinion, therefore, which have existed on this subject, have arisen from the different views taken of the nature of this power. But when the nature of a power like this is spoken of, when it is said that the nature of the power requires that it should be exercised exclusively by Congress', it ■must be intended to refer to the subjects of that power, and to say they are of such a nature as to require exclusive legislation by Congress. Now the power to regulate commerce, embraces a vast field, containing not only many, but exceedingly various subjects, quite unlike in their nature; some imperatively demanding a single uniform rule, operating equally on the commerce of the United States in every port; and some, like the subject now in question, as imperatively demanding that diversity, which alone can meet the local necessities of navigation.
Either absolutely to affirm, or deny that the nature of this power requires exclusive legislation by Congress, is to lose sight of the nature of the subjects of this power, and to assert concerning all of them,'what is really applicable but to,a part. Whatever subjects of this power are in their nature national, or admit only of one uniform system, or plan of regulation, may justly be said to be of such a nature as to require exclusive legislation by Congress. That this cannot be affirmed of laws for the regulation of pilots and pilotage is plain. The act of 1789 contains a clear and authoritative declaration by the first Congress, that the nature of this subject is such, that until Congress should find it necessary to exert its power, it should be left to the legislation of the States; that it is local and not national; that it is likely to be the best, provided , for, not by one system, or plan of regulations, but by as many as the legislative discretion of the several States should deem applicable to the local peculiarities of the ports within their limits.
Viewed in this light, so much of this act of 1789 as declares that pilots shall continue to be regulated “ by such laws as the States may respectively hereafter enact for that purpose,” instead of being held to be inoperative, as an attempt to confer on the States a power to legislate, of which the Constitution had de[320]*320prived th$m, is allowed an appropriate and important signification. It manifests the understanding of Congress, at the outset of the government, that the nature of this subject is not such as to require its exclusive legislation. The practice of the States, and of the national government, has been in conformity with this declaration, from the origin of the national government to this time; and the nature of the subject when examined, is such as to leave no doubt of the superior fitness and propriety, not to say the absolute necessity, of different systems of regulation, drawn from local knowledge and experience, and conformed to local wants. How then can we say, that by the mere grant of power to regulate commerce, the States are deprived of all the power to legislate on this subject, because from the nature of the power the legislation of Congress must be exclusive. This would be to affirm that the nature of the power is in any case, something different from the nature of the subject to which, in such, case, the power extends, and that the nature of the power necessarily demands, in all cases, exclusive legislation by Congress, while the nature of one of the subjects of that power, not only does not require such exclusive legislation, but may be best provided for by many different systems enacted by the States, in conformity with the circumstances of the ports within their limits. In construing an instrument designed, for the formation of a government, and in determining the extent of one of its important grants of power to legislate, we can make no such distinction between the nature of the power and the nature of the subject on which that power was intended practically to operate, nor consider the grant more extensive by affirming of the power, what is not true of its subject now in question.
It is the opinion of a majority of the court that the mere grant to ■ Congress of the power to regulate commerce, did not deprive the States of power to regulate pilots, and that although Congress has legislated on this subject, its legislation manifests an intention, with a single exception, not to regulate this subject, but to leave its regulation to the several States. To these precise questions, which are all we are called on to decide, this opinion must be understood to be confined. It does not extend to the question what other subjects, under the commercial power, are within the exclusive control of Congress, or may be regulated by the States in the absence of all congressional legislation; nor to the general question how far any regulation of a subject by Congress, may bé deemed to operate as an exclusion of all legislation by the States upon the same subject.- We decide the precise questions before us, upon what we deem sound principles, applicable to this particular subject in the state in which the legislation of Congress has left it. We go no further.
[321]*321We have not adverted to the practical consequences of holding that the States possess no power to legislate for the regulation of pilots, though in our apprehension these would be of the most serious importance. For more than sixty years this subject has been acted on by the States, and. the systems óf some of them created and of others essentially modified during that period. To hold that pilotage fees and penalties demanded and received during that time, have been illegally exacted, under color of void laws, would work an amount of mischief which a clear conviction of constitutional duty, if entertained, must force us to occasion, but which could be viewed by no just mind without deep regret. Nor would the mischief be limited-to the past. If Congress were now to pass a law adopting the existing State laws, if enacted without authority, and in violation of the Constitution, it would seem to us to be a new and questionable mofle of legislation.
If the grant of commercial power in the Constitution has deprived the States of all power to legislate for the regulation of pilots, if their laws on this subject are mere usurpations upon the exclusive power of the general government, and utterly void,. it may be doubted whether Congress could,, with propriety, recognize them as laws, and adopt them as its own acts; and how are the legislatures of the States to proceed in future, to watch over and amend these laws, as the progressive wants of a growing commerce will require, when the members of those legislatures are made aware that they cannot legislate on this subject without violating the oaths they have taken to support the Constitution of the United States 1
We are of opinion that this State law was enacted by virtue of a power, residing in the State to legislate; that it is not in conflict with any law of Congress; that it does not interfere with any system which Congress has established by making regulations, or by intentionally leaving individuals to their own unrestricted action ; that this law is therefore valid, and the judgment of the Supreme Court of Pennsylvania in each case must be affirmed.
Mr, Justice McLean and Mr. Justice Wayne dissented; and Mr. Justice Daniel, although he concurred in the judgment of the court, yet dissented from its reasoning.