The first census was taken in 1790. There were then less than four million people (3,929,214). In 1880, there were over fifty million (50,155,783). It is safe to estimate that, when the census of 1890 comes to be added up, there will be between sixty and seventy million, say sixteen or seventeen times as many as there were one hundred years before. As of 2020, the population of this country is the third highest in the world, after China and India, and we have over three hundred million people in the United States.

The increase of wealth has been yet more remarkable. This is due to the resources of the country, as well as to the enterprise of the people. Wheat from the rich farms of the great interior valley, and meat from the cattle ranges of the Western States and Territories, are sent across the sea in vast quantities. Gold and silver from the Rocky Mountains and the Pacific coast, petroleum from the neighborhood of the Alleghany Mountains, and supplies of coal and iron in various regions are great sources of wealth. Manufactures of many kinds also enrich the people. The United States is one of the richest of the nations.

In a new country, people become inventive, because they have to find out how to do things that they have never seen anybody do before. Americans are some of the most inventive people in the world. Before the Revolution, Thomas Godfrey, of Philadelphia, invented the quadrant, an instrument to help a navigator to find his whereabouts at sea. About the same time Franklin invented the lightning rod. There was also a valuable machine invented in South Carolina for doing the hard labor of taking the hull off of the grains of rice. This was run by the ebbing and flowing of the tide. In the middle colonies flour mills were improved, and little elevating machines invented, so that wheat did not have to be carried to the top of the mill on a person's back.

America was become celebrated for what are cotton gin. called labor-saving machines. One of the most remarkable of these is the cotton gin. It took so much time and toil to pick the seeds out of cotton that only small quantities were raised for home use. Long before the Revolution, a "gin" for cleaning the cotton of seed had been invented, but it did not come into general use. But, when machines for spinning cotton thread and weaving cotton cloth by steam power were invented in England, there sprang up a great demand for raw cotton. In 1794, Eli Whitney invented a "saw-gin" for taking the seeds out of cotton. This made cotton raising profitable, and caused the Southern States to grow rapidly in population and wealth. After the invention of the gin, indigo culture was quite driven out by cotton raising.

The cotton gin was the first of a great family of labor saving machines, partly or wholly invented in this country. Reaping- and mowing-machines were first made successful by American inventors. Threshing machines were improved here. All the agricultural machines now used have practically been introduced in the last fifty years. The first really successful sewing-machine was introduced by Elias Howe in 1845. Morse's telegraph came into use at about the same time. The telephone, a recent invention, enables people to hold conversation when far apart. The phonograph records speech on a cylinder, which may be sealed up and kept for a thousand years, when it can be made to repeat the very tones of the voice that spoke the words.

We live in a different world from that of our forefathers, who had only saddle horses or wagons for land conveyance, and slow sailing ships or row boats for water journeys. We can go around the world in a great deal less time than some of the first emigrants took to sail from England to America. Our ancestors had neither kerosene oil, gas, nor electric light. Stoves were practically unknown; for warming themselves and cooking their food, people in old times had only wood fires in wide, open fireplaces, which often chilled the room with draughts of air or filled it with smoke. They carded, spun, wove, and dyed, by hand, wool or flax for their own clothing. Now steam is made to do most of the work in spinning and weaving, in making hats and shoes, in planing boards, and in turning wood. Even delicate little things like watches are made mostly by steam machinery.

Out of the use of machinery has grown up the factory system, which gathers working people into towns and sets them to work together in factories. Many people are able in this way to labor on the same piece of work, each doing his own part. This saves time, and makes each person's toil more productive. The building and running of these factories require a great deal of money; so that work is now carried on by two classes: First, the capitalists, who furnish the factory and its machines; second, the workingmen, who receive wages and do the labor. This has led to great discussions of the rights of the working people, and those who furnish the money or capital.