The New York journals have recently contained estimates as to the probable population of the United States, to be furnished by the returns of the census. These publications are all said to have been founded upon partial reports, filed at Washington, or published in different newspapers. One of these estimates places the total population at thirty-two millions, and others at thirty millions and upwards.

Whatever may be the actual result, (which must very soon be known,) it is quite certain that the increase has been very large. In all portions of the country, with the exception of the New England States, the gain has been very considerable; but the Western States have been the theatre of the greatest increase. California, Oregon and Washington Territory, however, we may well say, have been built up within the past ten years; their population previously having been scarcely taken into account in making up the census reports, California returning 92,597, and Oregon 13,294, or a total population of only 105,891.

Although new States have been settled and added to the Union, in rapid succession, since the foundation of the Government, and the increase of numbers has been without a parallel in the history of the world, yet it is not population alone of which we can boast; it is also an increase in arts and manufacture—in all that constitutes civilized life. In every portion of the country, schools and colleges have been established, education encouraged, until from a small and insignificant Republic, we have grown to be an enlightened and powerful nation. And what is more, with all our contentions, the prosperity of the Union seems to be still upon the increase.

Nor is the prosperity of the United States confined to new States, or to the agricultural districts. It is seen in the cities and towns. Everywhere throughout the length and breadth of the land permanent improvements are being made, and in our cities perhaps the indications of such improvements are even more distinctly visible than elsewhere.

The tendency of population has been, latterly, to cities, not alone in the United States, but in Europe. In all manufacturing and commercial countries, since the construction of railroads and steamers, population has rapidly augmented in towns. Under some Governments the increase of population has been altogether in commercial and manufacturing centers, probably induced, to a great extent, by a supply of cheap food and material, furnished by modern improvements in the means of communication. Whatever may be the reason, the result is certain; population aggregates in cities, to an extent which was never before known. The publication of statistics show this point more and more distinctly.

As to what is to be the effect of this tendency of population to towns, time alone must determine. Whether such masses of humanity will eventually degenerate is a matter of speculation. It is, however, very certain that the aggregation of population tends to encourage manufactures, for, without this and trade, the inhabitants of crowded cities could not exist. Nor have the United States been favored alone by an increase of population, unprecedented in the annals of the world. They have a great variety of climate and productions. Indeed the variety is almost past conception. The United States are a world within themselves. The North furnishes the productions of a temperate clime—grain, cattle, sheep, etc. The South—cotton, tobacco, rice, sugar, etc. The West—the productions of both the other sections of the Union combined. Cole, iron, and the precious metals, are abundant in the Atlantic slope. And then, California, Oregon, Washington Territory, and Utah come in with a variety scarcely inferior to that of the other portions of the Union, with the addition of gold and silver in untold quantities.

Reflecting men, in casting their eyes over the United States, cannot avoid astonishment at the results which have been brought about within the last fifty years. In 1810, we had a population of seven millions. Today we have rising thirty millions. Fifty years ago, we were scarcely regarded throughout Europe as a civilized nation; but to-day, without our trade, Europe would become bankrupt. The laboring millions could scarcely be clothed without our cotton. The mills of England and France would stop without orders from the United States for their merchandise. The commerce of the United States with Europe we have seen placed recently, by a French publication, at the enormous sum of rising four thousand million francs, or eight hundred million dollars. By tables published in the United States, the commerce of this country—imports and exports—in 1858, amounted to over six hundred and seven million dollars. This commerce employs continually about nine thousand vessels.

Although we have an enormous commerce with foreign countries, yet there is scarcely an article imported from abroad, which we could not do without. We purchase untold amounts of merchandise, yet let non-intercourse with every other nation be declared today, and it is questionable whether any interest other than that of shipping would seriously suffer thereby. Our immense population could be fed and clothed almost as well as ever.

We say that there is within the limits of the United States, almost everything necessary to the support of its inhabitants. It has a variety of climate and production, and an enterprising population. Its inhabitants are free—no nobility thriving from its laborers. No standing army to support, and promotion open to the lowest citizen who has ability and industry. We ask, in all candor, if there is such another country for the poor man under heaven? Yet with all of this, there are unthinking persons here, who scarcely imagine, that the destruction of this Republic would be a serious loss.