Taking a broader view--for we might go on with the material details of progress all about us _ad infinitum_, did patience and strength hold out--we look abroad over the land, and note the great elements of a progress peculiarly American, in the growth and distribution of population, in manufactures, agriculture, and commerce. Each and all have been incalculably aided by perpetual invention. A few leading facts must suffice to show that our orators, in their most daring flights, can scarcely exaggerate the marvels of our material advance. The population of this country in 1776, including slaves, was about two and three quarters millions. In 1886, it is without doubt more than fifty millions. In 1790, when the first census was taken, the figure was a little less than four millions. A notable circumstance in reference to the movement of our population has been the increase of the proportion of dwellers in our cities to those in the rural districts. In 1790, only one-thirtieth of our population inhabited the cities. In 1886, probably nearly one-fourth are included in the cities. In 1790 there were but six cities with a population of more than eight thousand each. These were: Philadelphia, with about 42,500; New York, with about 33,000; Boston, with about 18,000; Charleston, with about 16,300: Baltimore, with about 13,500; and Salem, with a little over 8000. The total was about 131,500. Now the aggregate of our urban population is, probably, at least 12,000,000. It may be added that the _centre_ of our population has shifted from a few miles east of Baltimore, where it was in 1790, to about eight miles west by south from Cincinnati, where it is now supposed to be. [Sidenote: Agriculture.] The earliest avocation of our colonies was that of agriculture; and before 1776 our agricultural industries, owing to the discoveries which had gradually been made as to the capabilities of the then settled districts, had grown to important proportions. It needs but a glance at the map to observe over what a vast area agricultural enterprise has spread since 1790. We may fairly say that invention and improvement, in the application of chemistry and mechanical discovery to the cultivation of land, have kept pace with the territorial advance of agricultural science. There can scarcely be named a farming operation which is not performed by instruments far more perfect, and with a rapidity far greater, than was possible with our ancestors. [Sidenote: Cheaper Tools.]