66 Opinion of the Court. tation, and appointed commissioners to act with those from Virginia. The commissioners together re-run and re-marked the line as it was established in 1802, and planted such additional monuments as were deemed necessary, and they reported to their respective legislatures that they had accurately run, re-marked and measured the old line of 1802, with all its offsets and irregularities as shown in the surveyor's report" therein incorporated and on the accompanying map therewith submitted. The legislature of Tennessee approved of the action of the commissioners, but Virginia withheld her approval and called for a new appointment of commissioners to re-run and re-mark the line, which was refused by Tennessee as unnecessary. No complaint as to the correctness of the line run and established in 1802 was made by Virginia until within a recent period. She now by her bill asks that the compact entered into between her and the State of Tennessee, as set forth in the act of the general assembly of Virginia of January 22, 1803, and which became operative by similar action of the legislature of Tennessee on the 3d of November following, be declared null and void, as having been entered into between the States without the consent of Congress, and prays that this court will establish the true boundary line between those States due east and west, in latitude 36° and 30' north, in accordance with what it alleges to be the ancient chartered rights of that Commonwealth and the laws creating the State of Tennessee and admitting it into the Union. The Constitution provides that "no State shall, without the consent of Congress, lay any duty of tonnage, keep troops or ships of war in time of peace, enter into any agreement or compact with another State, or with a foreign power, or engage in war, unless actually invaded, or in such imminent danger as will not admit of delay.” Is the agreement, made without the consent of Congress, between Virginia and Tennessee, to appoint commissioners to run and mark the boundary line between them, within the prohibition of this clause? The terms "agreement" or "compact" taken by themselves are sufficiently comprehensive to How pedantic. Opinion of the Court. embrace all forms of stipulation, written or verbal, and relating to all kinds of subjects; to those to which the United States can have no possible objection or have any interest in interfering with, as well as to those which may tend to increase and build up the political influence of the contracting States, so as to encroach upon or impair the supremacy of the United States or interfere with their rightful management of particular subjects placed under their entire control. There are many matters upon which different States may agree that can in no respect concern the United States. If, for instance, Virginia should come into possession and ownership of a small parcel of land in New York which the latter State might desire to acquire as a site for a public building, it would hardly be deemed essential for the latter State to obtain the consent of Congress before it could make a valid agreement with Virginia for the purchase of the land. If Massachusetts, in forwarding its exhibits to the World's Fair at Chicago, should desire to transport them a part of the distance over the Erie Canal, it would hardly be deemed essential for that State to obtain the consent of Congress before it could contract with New York for the transportation of the exhibits through that State in that way. If the bordering line of two States should cross some malarious and diseaseproducing district, there could be no possible reason, on any conceivable public grounds, to obtain the consent of Congress for the bordering States to agree to unite in draining the district, and thus removing the cause of disease. So in case of threatened invasion of cholera, plague, or other causes of sickness and death, it would be the height of absurdity to hold that the threatened States could not unite in providing means to prevent and repel the invasion of the pestilence, without obtaining the consent of Congress, which might not be at the time in session. If, then, the terms "compact" or "agreement" in the Constitution do not apply to every possible compact or agreement between one State and another, for the validity of which the consent of Congress must be obtained, to what compacts or agreements does the Constitution apply? Opinion of the Court. We can only reply by looking at the object of the constitutional provision, and construing the terms "agreement" and "compact" by reference to it. It is a familiar rule in the construction of terms to apply to them the meaning naturally attaching to them from their context. Noscitur a sociis is a rule of construction applicable to all written instruments. Where any particular word is obscure or of doubtful meaning, taken by itself, its obscurity or doubt may be removed by reference to associated words. And the meaning of a term may be enlarged or restrained by reference to the object of the whole clause in which it is used. Looking at the clause in which the terms "compact" or "agreement appear, it is evident that the prohibition is directed to the formation of any combination tending to the increase of political power in the States, which may encroach upon or interfere with the just supremacy of the United States. Story, in his Commentaries, (§ 1403,) referring to a previous part of the same section of the Constitution in which the clause in question appears, observes that its language "may be more plausibly interpreted from the terms used, 'treaty, alliance or confederation,' and upon the ground that the sense of each is best known by its association (noscitur a sociis) to apply to treaties of a political character; such as treaties of alliance for purposes of peace and war; and treaties of confederation, in which the parties are leagued for mutual government, political coöperation, and the exercise of political sovereignty, and treaties of cession of sovereignty, or conferring internal political jurisdiction, or external political dependence, or general commercial privileges"; and that "the latter clause, 'compacts and agreements,' might then very properly apply to such as regarded what might be deemed mere private rights of sovereignty; such as questions of boundary; interests in land situate in the territory of each other, and other internal regulations for the mutual comfort and convenience of States bordering on each other." And he adds: "In such cases the consent of Congress may be properly required, in order to check any infringement of the rights of the national government; and, at the same time, a total prohibition to enter into Opinion of the Court. any compact or agreement might be attended with permanent inconvenience or public mischief." - cover all Compacts or agreements — and we do not perceive any difference in the meaning, except that the word "compact" is generally used with reference to more formal and serious engagements than is usually implied in the term "agreement" stipulations affecting the conduct or claims of the parties. The mere selection of parties to run and designate the boundary line between two States, or to designate what line should be run, of itself imports no agreement to accept the line run by them, and such action of itself does not come within the prohibition. Nor does a legislative declaration, following such line, that it is correct, and shall thereafter be deemed the true and established line, import by itself a contract or agreement with the adjoining State. It is a legislative declaration which the State and individuals, affected by the recognized boundary line, may invoke against the State as an admission, but not as a compact or agreement. The legislative declaration will take the form of an agreement or compact when it recites some consideration for it from the other party affected by it, for example, as made upon a similar declaration of the border or contracting State. The mutual declarations may then be reasonably treated as made upon mutual considerations. The compact or agreement will then be within the prohibition of the Constitution or without it, according as the establishment of the boundary line may lead or not to the increase of the political power or influence of the States affected, and thus encroach or not upon the full and free exercise of Federal authority. If the boundary established is so run as to cut off an important and valuable portion of a State, the political power of the State enlarged would be affected by the settlement of the boundary; and to an agreement for the running of such a boundary, or rather for its adoption afterwards, the consent of Congress may well be required. But the running of a boundary may have no effect upon the political influence of either State; it may simply serve to mark and define that which actually existed before, but was undefined and unmarked. In that case the agreement for the running of the line, or its actual survey, Opinion of the Court. would in no respect displace the relation of either of the States to the general government. There was, therefore, no compact or agreement between the States in this case which required, for its validity, the consent of Congress, within the meaning of the Constitution, until they had passed upon the report of the commissioners, ratified their action, and mutually declared the boundary established by them to be the true and real boundary between the States. Such ratification was mutually made by each State in consideration of the ratification of the other. The Constitution does not state when the consent of Congress shall be given, whether it shall precede or may follow the compact made, or whether it shall be express or may be implied. In many cases the consent will usually precede the compact or agreement, as where it is to lay a duty of tonnage, to keep troops or ships of war in time of peace, or to engage in war. But where the agreement relates to a matter which could not well be considered until its nature is fully developed, it is not perceived why the consent may not be subsequently given. Story says that the consent may be implied, and is always to be implied when Congress adopts the particular act by sanctioning its objects and aiding in enforcing them; and observes that where a State is admitted into the Union, notoriously upon a compact made between it and the State of which it previously composed a part, there the act of Congress, admitting such State into the Union, is an implied consent to the terms of the compact. Knowledge by Congress of the boundaries of a State, and of its political subdivisions, may reasonably be presumed, as much of its legislation is affected by them, such as relates to the territorial jurisdiction of the courts of the United States, the extent of their collection districts, and of districts in which process, civil and criminal, of their courts may be served and enforced. In the present case, the consent of Congress could not have preceded the execution of the compact, for, until the line was run, it could not be known where it would lie and whether or not it would receive the approval of the States. The preliminary agreement was not to accept a line run, whatever it |