In the absence of such causes, and with the abundant capacity of our country for feeding its people, I think it an extremely moderate statement if we say that by the end of the next century the English race in the United States will number at least six or seven hundred millions. It used to be said that so huge a people as this could not be kept together as a single national aggregate,--or, if kept together at all, could only be so by means of a powerful centralized government, like that of ancient Rome under the emperors. I think we are now prepared to see that this is a great mistake. If the Roman Empire could have possessed that political vitality in all its parts which is secured to the United States by the principles of equal representation and of limited state sovereignty, it might well have defied all the shocks which tribally-organized barbarism could ever have directed against it. As it was, its strong centralized government did _not_ save it from political disintegration. One of its weakest political features was precisely this,--that its "strong centralized government" was a kind of close corporation, governing a score of provinces in its own interest rather than in the interest of the provincials. In contrast with such a system as that of the Roman Empire, the skilfully elaborated American system of federalism appears as one of the most important contributions that the English race has made to the general work of civilization. The working out of this feature in our national constitution, by Hamilton and Madison and their associates, was the finest specimen of constructive statesmanship that the world has ever seen. Not that these statesmen originated the principle, but they gave form and expression to the principle which was latent in the circumstances under which the group of American colonies had grown up, and which suggested itself so forcibly that the clear vision of these thinkers did not fail to seize upon it as the fundamental principle upon which alone could the affairs of a great people, spreading over a vast continent, be kept in a condition approaching to something like permanent peace. Stated broadly, so as to acquire somewhat the force of a universal proposition, the principle of federalism is just this:--that the people of a state shall have full and entire control of their own domestic affairs, which directly concern them only, and which they will naturally manage with more intelligence and with more zeal than any distant governing body could possibly exercise; but that, as regards matters of common concern between a group of states, a decision shall in every case be reached, not by brutal warfare or by weary diplomacy, but by the systematic legislation of a central government which represents both states and people, and whose decisions can always be enforced, if necessary, by the combined physical power of all the states. This principle, in various practical applications, is so familiar to Americans to-day that