is, in the days of our great-greatgrandchildren.  I do not predict any such result, for there are discernible economic reasons for believing that there will be a diminution in the rate of increase.  The rate must nevertheless continue to be very great, in the absence of such causes as formerly retarded the growth of population in Europe.  Our modern wars are hideous enough, no doubt, but they are short.  They are settled with a few heavy blows, and the loss of life and property occasioned by them is but trifling when compared with the awful ruin and desolation wrought by the perpetual and protracted contests of antiquity and of the Middle Ages.  Chronic warfare, both private and public, periodic famines, and sweeping pestilences like the Black Death,—­these were the things which formerly shortened human life and kept down population.  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.