When the confederated States found it convenient to modify the conditions of their association by giving to the General Government direct access in some respects to the people of the States, instead of confining it to action on the States as such, they proceeded to frame the existing Constitution, adhering steadily to one guiding thought, which was to delegate only such power as was necessary and proper to the execution of specific purposes, or, in other words, to retain as much as possible consistently with those purposes of the independent powers of the individual States. For objects of common defense and security, they intrusted to the General Government certain carefully defined functions, leaving all others as the undelegated rights of the separate independent sovereignties. Such is the constitutional theory of our Government, the practical observance of which has carried us, and us alone among modern republics, through nearly three generations of time without the cost of one drop of blood shed in civil war. With freedom and concert of action, it has enabled us to contend successfully on the battlefield against foreign foes, has elevated the feeble colonies into powerful States, and has raised our industrial productions and our commerce which transports them to the level of the richest and the greatest nations of Europe. And the admirable adaptation of our political institutions to their objects, combining local self-government with aggregate strength, has established the practicability of a government like ours to cover a continent with confederate states.