The constitution prohibits the states from making laws on the value and circulation of money: if, notwithstanding this prohibition, a state passes a law of this kind, with which the interested parties refuse to comply because it is contrary to the constitution, the case must come before a federal court, because it arises under the laws of the United States. Again, if difficulties arise in the levying of import duties which have been voted by congress, the federal court must decide the case, because it arises under the interpretation of a law of the United States.

This rule is in perfect accordance with the fundamental principles of the federal constitution. The Union as it was established in 1789, possesses, it is true, a limited supremacy; but it was intended that within its limits it should form one and the same people.{148} Within those limits the Union is sovereign. When this point is established and admitted, the inference is easy; for if it be acknowledged that the United States constitute one and the same people within the bounds prescribed by their constitution, it is impossible to refuse them the rights which belong to other nations. But it has been allowed, from the origin of society, that every nation has the right of deciding by its own courts those questions which concern the execution of its own laws. To this it is answered, that the Union is in so singular a position, that in relation to some matters it constitutes a people, and that in relation to all the rest it is a nonentity. But the inference to be drawn is, that in the laws relating to these matters the Union possesses all the rights of absolute sovereignty. The difficulty is to know what these matters are; and when once it is resolved (and we have shown how it was resolved, in speaking of the means of determining the jurisdiction of the federal courts), no farther doubt can arise; for as soon as it is established that a suit is federal, that is to say, that it belongs to the share of sovereignty reserved by the constitution to the Union, the natural consequence is that it should come within the jurisdiction of a federal court.

Whenever the laws of the United States are attacked, or whenever they are resorted to in self-defence, the federal courts must be appealed to. Thus the jurisdiction of the tribunals of the Union extends and narrows its limits exactly in the same ratio as the sovereignty of the Union augments or decreases. We have shown that the principal aim of the legislators of 1789 was to divide the sovereign authority into two parts. In the one they placed the control of all the general interests of the Union, in the other the control of the special interest of its component states. Their chief solicitude was to arm the federal government with sufficient power to enable it to resist, within its sphere, the encroachments of the several states. As for these communities, the principle of independence within certain limits of their own was adopted in their behalf; and they were concealed from the inspection, and protected from the control, of the central government. In speaking of the division of the authority, I observed that this latter principle had not always been held sacred, since the states are prevented from passing certain laws, which apparently belong to their own particular sphere of interest. When a state of the Union passes a law of this kind, the citizens who are injured by its execution can appeal to the federal courts.

{The remark of the author, that whenever the laws of the United States are attacked, or whenever they are resorted to in self-defence, the federal courts must be appealed to, which is more strongly expressed in the original, is erroneous and calculated to mislead on a point of some importance. By the grant of power to the courts of the United States to decide certain cases, the powers of the state courts are not suspended, but are exercised concurrently, subject to an appeal to the courts of the United States. But if the decision of the state court is in favor of the right, title, or privilege claimed under the constitution, a treaty, or under a law of congress, no appeal lies to the federal courts. The appeal is given only when the decision is against the claimant under the treaty or law. See 3d Cranch, 268. 1 Wheaton, 304.—American Editor.}

Thus the jurisdiction of the general courts extends not only to all the cases which arise under the laws of the Union, but also to those which arise under laws made by the several states in opposition to the constitution. The states are prohibited from making ex-post-facto laws in criminal cases; and any person condemned by virtue of a law of this kind can appeal to the judicial power of the Union. The states are likewise prohibited from making laws which may have a tendency to impair the obligations of contracts.{149} If a citizen thinks that an obligation of this kind is impaired by a law passed in his state, he may refuse to obey it, and may appeal to the federal courts.{150}

This provision appears to me to be the most serious attack upon the independence of the states. The rights awarded to the federal government for purposes of obvious national importance are definite and easily comprehensible; but those with which this last clause invests it are not either clearly appreciable or accurately defined. For there are vast numbers of political laws which influence the obligations of contracts, which may thus furnish an easy pretext for the aggressions of the central authority.

{The fears of the author respecting the danger to the independence of the states of that provision of the constitution, which gives to the federal courts the authority of deciding when a state law impairs the obligation of a contract, are deemed quite unfounded. The citizens of every state have a deep interest in preserving the obligation of the contracts entered into by them in other states: indeed without such a controlling power, "commerce among several states" could not exist. The existence of this common arbiter is of the last importance to the continuance of the Union itself, for if there were no peaceable means of enforcing the obligations of contracts, independent of all state authority, the states themselves would inevitably come in collision in their efforts to protect their respective citizens from the consequences of the legislation of another state.

M. De Tocqueville's observation, that the rights with which the clause in question invests the federal government "are not clearly appreciable or accurately defined," proceeds upon a mistaken view of the clause itself. It relates to the obligation of a contract, and forbids any act by which that obligation is impaired. To American lawyers, this seems to be as precise and definite as any rule can be made by human language. The distinction between the right to the fruits of a contract, and the time, tribunal, and manner, in which that right is to be enforced, seems very palpable. At all events, since the decision of the supreme court of the United States in those cases in which this clause has been discussed, no difficulty is found, practically, in understanding the exact limits of the prohibition.

The next observation of the author, that "there are vast numbers of political laws which influence the obligations of contracts, which may thus furnish an easy pretext for the aggressions of the central authority," is rather obscure. Is it intended that political laws may be passed by the central authority, influencing the obligation of a contract, and thus the contracts themselves be destroyed? The answer to this would be, that the question would not arise under the clause forbidding laws impairing the obligation of contracts, for that clause applies only to the states and not to the federal government.

If it be intended, that the states may find it necessary to pass political laws, which affect contracts, and that under the pretence of vindicating the obligation of contracts, the central authority may make aggressions on the states and annul their political laws:—the answer is, that the motive to the adoption of the clause was to reach laws of every description, political as well as all others, and that it was the abuse by the states of what may be called political laws, viz.: acts confiscating demands of foreign creditors, that gave rise to the prohibition. The settled doctrine now is, that states may pass laws in respect to the making of contracts, may prescribe what contracts shall be made, and how, but that they cannot impair any that are already made.