In addition to the dangers to the Constitution springing from the sources I have stated, there has been one which was perhaps greater than all.  I allude to the materials which this subject has afforded for sinister appeals to selfish feelings, and the opinion heretofore so extensively entertained of its adaptation to the purposes of personal ambition.  With such stimulus it is not surprising that the acts and pretensions of the Federal Government in this behalf should some times have been carried to an alarming extent.  The questions which have arisen upon this subject have related—­To the power of making internal improvements within the limits of a State, with the right of territorial jurisdiction, sufficient at least for their preservation and use.  To the right of appropriating money in aid of such works when carried on by a State of by a company in virtue of State authority, surrendering the claim of jurisdiction; and To the propriety of appropriation for improvements of a particular class, viz, for light houses, beacons, buoys, public piers, and for the removal of sand bars, sawyers, and other temporary and partial impediments in our navigable rivers and harbors.  The claims of power for the General Government upon each of these points certainly present matter of the deepest interest.  The first is, however, of much the greatest importance, in as much as, in addition to the dangers of unequal and improvident expenditures of public moneys common to all, there is super-added to that the conflicting jurisdictions of the respective governments.  Federal jurisdiction, at least to the extent I have stated, has been justly regarded by its advocates as necessarily appurtenant to the power in question, if that exists by the Constitution.

That the most injurious conflicts would unavoidably arise between the respective jurisdictions of the State and Federal Governments in the absence of a constitutional provision marking out their respective boundaries can not be doubted.  The local advantages to be obtained would induce the States to overlook in the beginning the dangers and difficulties to which they might ultimately be exposed.  The powers exercised by the Federal Government would soon be regarded with jealousy by the State authorities, and originating as they must from implication or assumption, it would be impossible to affix to them certain and safe limits.

Opportunities and temptations to the assumption of power incompatible with State sovereignty would be increased and those barriers which resist the tendency of our system toward consolidation greatly weakened.  The officers and agents of the General Government might not always have the discretion to abstain from intermeddling with State concerns, and if they did they would not always escape the suspicion of having done so.  Collisions and consequent irritations would spring up; that harmony which should ever exist between the General Government and each member of the Confederacy would be frequently interrupted; a spirit of contention would be engendered and the dangers of disunion greatly multiplied.