The tenth article of the Amendments of the Constitution provides that "The powers not delegated to the United States by the Constitution,nor prohibited by it to the States,are reserved to the States respectively,or to the people."The powers thus reserved,are not only reserved against the Federal Government in whole,but against each and every department thereof.The judiciary is no more excepted out of the reservation than is the legislature or the Executive.Of what nature,then,are those reserved powers?Not the powers,if any such there be,which are possessed by all the States together,for the reservation is to "the States respectively";that is,to each State separately and distinctly.Now we can form no idea of any power possessed by a State as such,and independent of every other State,which is not,in its nature,a sovereign power.Every power so reserved,therefore,must be of such a character that each State may exercise it,without the least reference to responsibility to any other State whatever.

We have already seen that the Constitution of the United States was formed by the States as such,and the reservation above quoted is an admission that in performing that work,they acted as independent and sovereign States.

It is incident to every sovereignty to be alone the judge of its own compacts and agreements.No other State or assemblage of States has the least right to interfere with it,in this respect,and cannot do so without impairing its sovereignty.The Constitution of the United States is but the agreement which each State has made,with each and all the other States,and so distinguishable,in the principle we are examining,from any other agreement between sovereign States.Each State,therefore,has a right to interpret that agreement for itself,unless it has clearly waived that right in favor of another power.That the right is not waived in the case under consideration,is apparent from the fact already stated,that if the judiciary be the sole judges of the extent of their own powers,their powers are universal,and the enumeration in the Constitution is idle and useless.But it is still farther apparent from the following view:

The Federal Government is the creature of the States.It is not a party to the Constitution,but the result of it ?the creation of that agreement which was made by the States as parties.It is a mere agent,entrusted with limited powers for certain specific objects;which powers and objects are enumerated in the Constitution.Shall the agent be permitted to judge of the extent of his own powers,without reference to his constituent?

To a certain extent,he is compelled to do this,in the very act of exercising them,but this is always in subordination to the authority by whom his powers were conferred.If this were not so,the result would be,that the agent would possess every power which the constituent could confer,notwithstanding the plainest and most express terms of the grant.This would be against all principle and all reason.If such a rule would prevail in regard to government,a written constitution would be the idlest thing imaginable.

It would afford no barrier against the usurpations of the government,and no security for the rights and liberties of the people.If then the Federal Government has no authority to judge,in the last resort,of the extent of its own powers,with what propriety can it be said that a single department of that government may do so?Nay,it is said that this department may not only judge for itself,but for the other departments also.This is an absurdity as pernicious as it is gross and palpable.If the judiciary may determine the powers of the Federal Government,it may pronounce them either less or more than they really are.That government at least would have no right to complain of the decisions of an umpire which it had chosen for itself and endeavored to force upon the States and the people.Thus a single department might deny to both the others salutary powers which they really possessed,and which the public interest or the public safety might require them to exercise;or it might confer on them powers never conceded,inconsistent with private right,and dangerous to public liberty.

In construing the powers of a free and equal government,it is enough to disprove the existence of any rule,to show that such consequences as these will result from it.Nothing short of the plainest and most unequivocal language should reconcile us to the adoption of such a rule.No such language can be found in our Constitution.The only clause,from which the rule can be supposed to be derived,is that which confers jurisdiction in "all cases arising under the Constitution,and the laws made in pursuance thereof";