The decades between the Civil War and World War I were also an epoch of rapid population growth and urbanization. Between 1870 and 1900 national population nearly doubled from 40 million to 76 million, while the population of cities tripled from 10 million to 30 million.

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Year after year an endless stream of hopeful emigrants from American farms and European villages poured into the anonymous teeming cities of tenements and skyscrapers. These migrants were living now not merely in a new community, but in a setting so unfamiliar and disjointed that many doubted it deserved the term community at all.

Most of the new urban dwellers were also living in a new country. In the thirty years between 1870 and 1900, nearly 12 million persons immigrated to the United States, more than had come to our shores in the previous two and a half centuries. In the following fourteen years nearly another 13 million would arrive. In 1870 one-third of all industrial workers in America were foreign born. By 1900 more than half were. In 1890, immigrant adults actually outnumbered native adults in eighteen of the twenty cities with a population over 100,000.

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To those who lived through this epoch, what was most striking was simply the overwhelmingly accelerated pace of change itself. We often speak easily about the rapid pace of change in our own time. However, nothing in the experience of the average American at the end of the twentieth century matches the wrenching transformation experienced at the beginning of the century by an immigrant raised as a peasant in a Polish village little changed from the sixteenth century who within a few years was helping to construct the avant-garde skyscrapers of Louis Sullivan in the city of ‘big shoulders’ besides Lake Michigan. Even for native-born Americans, the pace of change in the last decades of the nineteenth century was extraordinary. A Bostonian Henry Adams later wrote of his own boyhood, ‘The American boy of 1854 stood nearer the year 1 t

In the nineteenth century, the population multiplied by a factor of almost fifteen, from 5.3 million to 76 million, a total larger than any European country except Russia. By 1890, 80 percent of New York’s citizens were immigrants or the children of immigrants, as were 87 percent of Chicago’s.

Three hundred years ago, 2 percent of the world's population lived in cities. Two hundred years ago, it was 10 percent. But the Industrial Revolution's steam-powered punch forever altered those numbers. Between 1870 and 1920, 11 million Americans left the country for the city. In Europe, 25 million more crossed an ocean to settle, predominantly, in US cities. By 1900, 40 percent of the United States had urbanized. By 1950, it was 50 percent. By the turn of the millennium, 80 percent.

Three hundred years ago, 2 percent of the world’s population lived in cities. Two hundred years ago, it was 10 percent. But the Industrial Revolution’s steam-powered punch forever altered those numbers. Between 1870 and 1920, 11 million Americans left the country for the city. In Europe, 25 million more crossed an ocean to settle, predominantly, in US cities. By 1900, 40 percent of the United States had urbanized. By 1950, it was 50 percent. By the turn of the millennium, 80 percent.

Hysteria will not help us to solve the problem that confronts us. We overstate the danger when we say that twelve millions seek, because of post-war conditions abroad, to come immediately to America. Ending June 30, 1914, the year's immigration figures were 1,218,480. Then came the war and a vast slump, from which we are just recovering. Calculations placed immigration statistics for the current year as 1,079,428—figures still below the prewar status. But even though we need have no grave fears, now is the time for a careful reexamination and revision of our immigration policies. We should have no more aliens to cope with, in the immediate months to come, than our institutions are able to handle. To assume burdens we can not easily meet would lie unfair both to us and to the alien. In protecting ourselves we are protecting him as well. We can not lower our standards, or allow them to be lowered, so as to include him. We must prepare him for our standards. And that means wise education. In the home, in the school, in industry, in citizenship, we have not heretofore applied thoroughly the human test, and that is our next step in the Americanization of the alien. Much work has yet to be done in the immediate months to come. Some protective measure, therefore, seems necessary.

During the sixty years between 1910 and 1970, the percentage of Americans living in urban areas of 2,500 or more rose from 45.7 to 73.5, and the number of urbanites more than tripled from 42 to 150 million. Urbanization clearly has brought important benefits to people… But this overwhelming tendency of people to concentrate in cities has worsened the environment through crowding, traffic congestion, delays and loss of time, and the over-loading of transportation, marketing and living facilities.

In 1900, two-thirds of the nation's... citizens still lived in rural communities... But that was changing rapidly (by 1920 more than half of all Americans lived in cities), thanks in large part to the explosive growth of manufacturing. ...[T]wo-thirds of the nation's output was in manufactured goods, even though manufacturing employed less than a quarter of the work force. The average plant producing petroleum, iron and steel, and textiles (the three leading industries)... were belied by the behemoth factories... Carnegie... christened the new century by selling his sprawling steel interests to J. P. Morgan, who promptly assembled the $1.4 billion United States Steel Corporation in 1901, the nation's first billion-dollar industry.
Still, American manufacturing was then churning out a tiny fraction—roughly 1 percent...—of what today's cleaner and enormously more efficient plants produce.

The century of revolution in the United States after the Civil War was economic, not political, freeing households from an unremitting daily grind of painful manual labor, household drudgery, darkness, isolation, and early death. Only one hundred years later, daily life had changed beyond recognition. Manual outdoor jobs were replaced by work in air-conditioned environments, housework was increasingly performed by electric appliances, darkness was replaced by light, and isolation was replaced not just by travel, but also by color television images bringing the world into the living room. Most important, a newborn infant could expect to live not to age forty-five, but to age seventy-two. The economic revolution of 1870 to 1970 was unique in human history, unrepeatable because so many of its achievements could happen only once.

It is a truism, of course, but it is none the less a fact which we must never forget, that this continent and this American community have been blessed with an unparalleled capacity for assimilating peoples of varying races and nations. The continuing migration which in three centuries has established here this nation of more than a hundred million, has been the greatest that history records as taking place in any such brief period. Viewing it historically, we find that the migration to America was little more than a westward projection of the series of great movements of peoples, by which Europe was given its present population. But there is a striking difference between the migrations into Europe, and the later movements of the same racial elements to the New World.

A million and a half of people spread over the Atlantic seaboard might be thought no great number; but it was a new thing in the world. ...which had in fact been carefully noted by Benjamin Franklin in a pamphlet on The Increase of Mankind, Peopling of Countries, etc.—that within three-quarters of a century the population of the continental colonies had doubled every twenty-five years, whereas the population of Old England during a hundred years past had not doubled once and now stood at only some six and a half millions. ...With these facts in mind, one might indeed say that a people with so much vitality and expansive power was abundantly able to pay taxes; but perhaps it was also a fair inference, if any one was disposed to press the matter, that unless it was so minded, such a people was already, or assuredly soon would be, equally able not to pay them.

Thanks to mass immigration, America has experienced greater demographic change in the last few decades than any other country in history has undergone during peacetime . . . If you grew up in America, suddenly nothing looks the same. Your neighbors are different. So is the landscape and the customs and very often the languages you hear on the street. You may not recognize your own hometown. Human beings aren’t wired for that . . . [W]e are told these changes are entirely good . . . We must celebrate the fact that a nation that was overwhelmingly European, Christian, and English-speaking fifty years ago has become a place with no ethnic majority, immense religious pluralism, and no universally shared culture or language.

1815 to 1914 was a period of both rapid technological development and rapid globalization.

There were experiences in previous centuries which might well have challenged this unqualified optimism. But the expansion of man's power over nature proceeded at such a pace that all doubts were quieted, allowing the nineteenth century to become the “century of hope” and to express the modern mood in its most extravagant terms. History, refusing to move by the calendar, actually permitted the nineteenth century to indulge its illusions into the twentieth. Then came the deluge. Since 1914 one tragic experience has followed another, as if history had been designed to refute the vain delusions of modern man.

Over the course of six decades, some six million black southerners left the land of their forefathers and fanned out across the country for an uncertain existence in nearly every other corner of America. The Great Migration would become a turning point in history. It would transform urban America and recast the social and political order of every city it touched. It would force the South to search its soul and finally to lay aside a feudal caste system. It grew out of the unmet promises made after the Civil War and, through the sheer weight of it, helped push the country toward the civil rights revolutions of the 1960s.