The successive decennial returns of the census since the adoption of the Constitution have revealed a law of steady, progressive development, which may be stated in general terms as a duplication every quarter century.  Carried forward from the point already reached for only a short period of time, as applicable to the existence of a nation, this law of progress, if unchecked, will bring us to almost incredible results.  A large allowance for a diminished proportional effect of emigration would not very materially reduce the estimate, while the increased average duration of human life known to have already resulted from the scientific and hygienic improvements of the past fifty years will tend to keep up through the next fifty, or perhaps hundred, the same ratio of growth which has been thus revealed in our past progress; and to the influence of these causes may be added the influx of laboring masses from eastern Asia to the Pacific side of our possessions, together with the probable accession of the populations already existing in other parts of our hemisphere, which within the period in question will feel with yearly increasing force the natural attraction of so vast, powerful, and prosperous a confederation of self-governing republics and will seek the privilege of being admitted within its safe and happy bosom, transferring with themselves, by a peaceful and healthy process of incorporation, spacious regions of virgin and exuberant soil, which are destined to swarm with the fast-growing and fast-spreading millions of our race.

These considerations seem fully to justify the presumption that the law of population above stated will continue to act with undiminished effect through at least the next half century, and that thousands of persons who have already arrived at maturity and are now exercising the rights of freemen will close their eyes on the spectacle of more than 100,000,000 of population embraced within the majestic proportions of the American Union.  It is not merely as an interesting topic of speculation that I present these views for your consideration.  They have important practical bearings upon all the political duties we are called upon to perform.  Heretofore our system of government has worked on what may be termed a miniature scale in comparison with the development which it must thus assume within a future so near at hand as scarcely to be beyond the present of the existing generation.

It is evident that a confederation so vast and so varied, both in numbers and in territorial extent, in habits and in interests, could only be kept in national cohesion by the strictest fidelity to the principles of the Constitution as understood by those who have adhered to the most restricted construction of the powers granted by the people and the States.  Interpreted and applied according to those principles, the great compact adapts itself with healthy ease and freedom to an unlimited extension of that benign system of federative self-government of which it is our glorious and, I trust, immortal charter.  Let us, then, with redoubled vigilance, be on our guard against yielding to the temptation of the exercise of doubtful powers, even under the pressure of the motives of conceded temporary advantage and apparent temporary expediency.