It is apparent from what has been said in the preceding chapter relating to the general jurisdiction of the state courts, that it would have been possible to provide for a federal government without a judicial department; for all cases, whether involving the federal or state law, might have been tried in the courts of the states. Under the Articles of Confederation there was no provision whatever for a federal judiciary, although Congress could appoint courts for the trial of piracies and felonies on the high seas and also prize courts (Art. IX). But, on the other hand, a sovereign government would be lame and impotent indeed which should depend for the interpretation of its constitution and statutes, and the determination of the powers of its departments, so far as they might be judicially called in question, upon the decisions of the courts of the respective states of which it should be composed. An immediate and practical difficulty would be that the courts of the different states might well entertain diverse views as to the construction of the constitution and statutes of the United States, and the federal law, which is the supreme law of the land, might in fact be one thing in Massachusetts and another thing in Virginia. It was therefore necessary to the stability and perpetuity of the Union that there should be federal courts, in which the rights of parties depending upon the constitution and statutes of the United States could be ultimately decided.

For some other purposes, also, it was essential that there should be federal courts. For instance, it would greatly embarrass the relations of the federal government with foreign governments if the ambassadors, public ministers, and consuls of foreign countries, while in this country, should be subject to the jurisdiction of courts not constituting a part or department of the federal government. Moreover, as to navigation on the high seas, it is important that there be federal courts to determine controversies relating thereto, for the ships of the United States, while on the high seas, are deemed a part of United States territory, although they are beyond the jurisdiction of any state.

Furthermore, it is important that there be courts in which the federal government may prosecute crimes against the laws of the United States, and bring civil suits, in the public interest, against individuals; and it would be embarrassing and inconvenient for that government to be compelled to prosecute these suits in state courts. In these classes of cases, at least, it is essential to the dignity and sovereignty of the federal government that there be federal courts in which such controversies may be determined.

But there are other classes of cases in which it may be desirable that there be a tribunal other than the state courts for the determination of controversies in which the federal government has not essentially any direct interest. For instance, in controversies between two states respecting their boundaries it would not be expedient to allow the courts of either state to render a final decision. It could not be expected that either state would be satisfied with a decision in such a matter rendered in the courts of the other state. Likewise, in controversies between a state and citizens of another state, or between citizens of different states, or between citizens of a state and foreign states, citizens or subjects, it is highly desirable that the final jurisdiction should be in some court of higher authority than the courts of a state. In cases pertaining to any one of these classes last enumerated, the federal government has no direct interest, except to furnish 'a tribunal, impartial as between the parties, and removed from suspicion of local influence, and whose decisions would be likely to command the respect of the parties concerned. This branch of the jurisdiction of the federal courts may therefore be said to be required as a matter of expediency, although not essential to the sovereignty and independence of the federal government.