The First Measured Century: An Illustrated Guide to Trends in American, 1900-2000

Chapter One

The American population nearly quadrupled during the twentieth century. The annual rate of population growth fluctuated until about 1960, when a distinctly lower growth rate ensued.

Rapidly falling death rates, massive immigration, and a "baby boom" in mid-century caused the American population to expand at an extraordinary rate, doubling in the first half of the century and almost doubling again in the second half (see upper chart). At the same time, the world population grew by almost the same factor of four. Thus, the American population constituted about the same fraction of the world population—4.5 percent—in 2000 as it did in 1900.

Most of the decline in death rates occurred in the early part of the century, primarily among children. Immigration rates were also highest in the early part of the century. The baby boom, which lasted from 1946 to 1964, added 76 million babies to the U.S. population.

While the population increased steadily throughout the century, the annual rate of growth varied (see lower chart). The smallest increase occurred from 1918 to 1919, when more than 100,000 U.S. soldiers died during World War I (see page 206) and more than half a million Americans died from a virulent strain of influenza that swept the nation (see page 136). The growth rate slowed again after Congress enacted restrictions on immigration in 1921 and 1924. A sharp drop in birth rates during the Depression caused a significant decline in the population growth rate. Despite these variations in the growth rate, however, the U.S. population continued toincrease every year—even during World War II, despite battle deaths, diminished fertility due to the deployment of millions of soldiers, and a sharp drop in immigration. Fertility rates also fell dramatically after the baby boom, but immigration helped sustain a population growth rate of about 1 percent a year through the end of the century (see pages 84 and 14).

If these trends in fertility and immigration persist, the American population will continue to grow in the early twenty-first century, although at a diminishing rate. The U.S. Census Bureau's "middle series" projection indicates a population of 300 million in 2011.

The life expectancy of Americans increased dramatically
first for infants and children, then for adults.

Life expectancy at birth increased by twenty-six years for males and twenty-nine years for females during the century (see upper chart). Driven principally by a decrease in infant (up to age one) mortality, most of this improvement occurred by 1950 (see page 134).

At midcentury, many experts believed that any gains in extending the lives of mature adults would come very slowly. This did not turn out to be the case. Life expectancy increased at age sixty, age seventy, and all intermediate ages (see page 136). In 1950, a sixty-year-old white female could expect to live to be seventy-nine years old. Her counterpart in 1996 could expect to live to be eighty-three years old—a four-year increase in expected life length (see lower chart).

The female advantage in life expectancy at birth increased throughout the century. The difference ranged from about three years in 1900 to nearly six years in 1996. The relative increase was even greater at later ages. This widening margin was often attributed to safer and less frequent childbearing, but that does not explain the existence of this gender gap to begin with. No one fully understands why women are more durable than men, but the fact is unmistakable.

These trends in life expectancy are based on data for white Americans. The life expectancy at birth for nonwhite Americans was thirty-three years in 1900—fifteen years lower than the life expectancy of forty-eight years for whites. This gap declined throughout the century, narrowing to seven years by 1996.

The proportion of children and adolescents in the population
declined, while the proportion of older people increased
throughout the century

These two phenomena follow mechanically from the falling birth rate and rising average length of life. As the birth rate falls, the ratio of children to adults necessarily diminishes and the average age of the population rises. As people live longer on average, the proportion of the population at older ages necessarily becomes larger.

Because the decline in the birth rate was almost continuous (with the exception of the baby boom) and the lengthening of lifetimes fully continuous, the proportion of children and adolescents in the population decreased steadily from 44 percent in 1900 to 29 percent in 1998. If the birth rate declines further or remains stable and average lifetimes continue to lengthen, the youthful component of the population will continue to decrease. The Census Bureau's middle series projection indicates that children and adolescents will constitute barely a fifth of the population by 2020.

These changes at both ends of the age spectrum did not have much impact on the relative size of the intermediate group between the ages of twenty and fifty-nine. This segment represented roughly 50 percent of the population throughout the twentieth century, and this is not expected to change much in the twenty-first. That percentage is important because it represents a ratio of 1:1 between people of working age, the great majority of whom are economically active, and their individual or collective dependents.

During the first half of the century, the proportion of centenarians in the population declined, but in the last two decades of the century that age group increased more than any other.

This is one of the most puzzling trends in this book. From 1900 to 1950, the proportion of the population that had attained or surpassed the age of one hundred years declined with each census. While life expectancy was increasing dramatically at younger ages, the number of centenarians per million Americans dropped from forty-six in 1900 to fifteen in 1950. One possible explanation is that the centenarians of 1900, who were born in 1800 or earlier and had much less schooling than the centenarians of 1950, were more likely to be misinformed about their own birth dates or to overestimate their ages. A second possibility is that more members of the 1900 cohort had experienced a healthy rural upbringing whose benefits lasted a lifetime. A third possible explanation is that the huge influx of young migrants and the large number of births during those years caused the total population to grow much faster than the population of centenarians, thereby effecting a decline in the number of centenarians per million population.

The number of centenarians per million population was roughly the same in 1975 as in 1900. By 2000, however, the number had escalated to 262 per million. According to Census Bureau estimates, 72,000 centenarians were alive in 2000—enough to fill a fair-sized city.

Unlike life expectancy, which changes from year to year, the human life span (maximum longevity) seems to have been fixed throughout history. Despite the claims made for the exceptional longevity of Russian Georgians or Bolivian mountaineers, there is no reliable record of any human surviving past the age of 122.

As the nation grew, the share of the population living in the Northeast and Midwest declined, while the share residing in the West grew rapidly and the South remained the most populous region

In 1900, the majority of Americans lived in the colder sections of the country, the Northeast and Midwest (see upper charts). By 1990, the majority lived in the West and South, areas of relatively mild winters and hot summers (see lower charts). The spread of household air conditioning after World War II played a key role in this transformation.

A significant portion of this population shift can be traced to the exceptional growth of California. In 1900, 1.5 million people resided in the state, making it the twenty-first largest in the nation. By 2000, California's population had grown to 33 million, making it almost as large as the next two most populous states (Texas and New York) combined.

Although the Census Bureau considers Texas a southern state, Texans often argue that it is a western state. If Texas were included with the western states, the West would have been the most populous region of the country at the end of the century.

At the beginning of the century, the American people were mostly rural. At the end, they were largely urban. Most of these urban dwellers lived in the suburbs.

The migration from rural areas to the cities and from cities to the suburbs changed the face of the nation at least as much as the movement between regions. At the beginning of the century, 60 percent of the population lived in or around places with fewer than 2,500 inhabitants, and most were involved in farming. In 1990, only 25 percent lived within or in the vicinity of such small communities, and very few had any connection with farming (see page 26).

The cities grew rapidly during the first half of the century, as rural people left the land and the immigrants of the early 1900s flowed into the cities (see upper chart). The combined population of the ten largest American cities in 1900 was slightly more than 9 million. The ten largest cities of 1950 had about 22 million residents. Because so many people left the cities for the suburbs during the second half of the century, most cities experienced little growth and many actually lost population. The ten largest cities of 1998 had about the same combined population as those of 1950.

The growth of the nation's suburbs, in contrast, continued throughout the century. The share of the U.S. population that lived in the suburbs doubled from 1900 to 1950 and doubled again from 1950 to 2000 (see lower chart). Frequently, the suburbs of one city expanded until they encountered the suburbs of another, creating urban corridors such as those that connect Chicago and Milwaukee or San Jose and San Francisco. Some of these corridors combined to create even larger configurations. At the end of the century, an urban corridor extended more than 700 miles from Norfolk, Virginia, to Portland, Maine.

Two great waves of immigration swelled the American population and changed its composition

From the founding of the Republic in 1789 until 1880, the great majority of immigrants were from Northern and Western Europe (especially Great Britain, Germany, Ireland, and Scandinavia). Most of the Irish and some of the Germans were Catholic, but the great majority of new Americans were Protestant. In the great wave of immigration that began around 1880, the newcomers came predominantly from Southern and Eastern Europe (especially Poland, Russia, and Italy). They were Catholic, Jewish, or Eastern Orthodox, and concern that they were changing the national character ultimately led to stricter controls on immigration, which prevailed from 1924 to 1965.

The Immigration Act of 1965, which eliminated ethnic and racial restrictions on immigrants, engendered major change in the U.S. population. "The bill will not flood our cities with immigrants," said one of its sponsors. "It will not upset the ethnic mix of our society." But the new law produced very different, largely unanticipated consequences.

The ensuing surge of immigration was dominated by new arrivals from the Western Hemisphere, especially Mexico and the Caribbean islands, and from Asia, particularly Korea, Vietnam, the Philippines, and China. A substantial number of Muslims immigrated to the United States. For the first time since the end of the illegal slave trade in the 1850s, a sizable contingent of immigrants came from sub-Saharan Africa. In 1998, barely 3 percent of immigrants came from Britain, Germany, Ireland, and Scandinavia.

The bar representing 1965-1998 on the graph includes about 3 million illegal foreign residents who took advantage of an amnesty offered by Congress to obtain legal residence between 1988 and 1991. It does not include 5 million others who, according to the Immigration and Naturalization Service, entered the country illegally or overstayed temporary visas between 1965 and 1998 and were not legalized. The largest number of them came from Mexico, but many other countries were represented.

The size of the foreign-born population in the United States
fluctuated in response to changing immigration policies

During the twentieth century, the nation recorded its highest percentage of foreign-born residents—14.7 percent of the U.S. population—in 1910. Although the foreign born constituted less than 10 percent of the population in 1999, they represented the largest number of foreign-born residents—nearly 26 million—in U.S. history.

These foreign-born residents differed significantly from the nation's native population. Compared with natives, the foreign-born population included fewer children and adolescents and more young adults. Hispanics and Asians constituted 68 percent of the foreign born but only 9 percent of natives.

The educational level of the foreign born was distinctly lower: 35 percent of foreign-born adults did not have a high school education compared with only 16 percent of natives. The employment rate of the foreign born was similar to that of natives, but their earnings were much lower. More than a fifth of the foreign-born population was classified as poor compared with an eighth of the native population. As a group, the foreign born used more than a proportionate share of social services.

These circumstances were not permanent, however. As individual immigrants remained in America, their social and economic well-being tended to improve rapidly. At the close of the century, for example, immigrants who came to the United States in the 1990s had very low rates of home ownership, but foreign-born residents who arrived before 1970 had a higher rate of home ownership than natives.

During the second half of the century, the proportion of
minorities in the population increased dramatically.

The federal government officially recognizes four population groups that are entitled to the benefits of minority preference programs: (1) American Indian or Alaska Native; (2) Asian or Pacific Islander; (3) Black; and (4) Hispanic.

There is nothing rational or scientific about this classification. By mixing genealogy, geography, culture, and personal history, it produces many anomalies. Based on an arbitrary rule developed to meet the property requirements of slavery, blacks are defined as people with even a small fraction of African ancestry. Through a series of compromises worked out under the reservation system, American Indians are people with some minimum percentage of tribal ancestry (the percentages vary from tribe to tribe and change from time to time). Asians and Pacific Islanders are people who were born anywhere in Asia or the unrelated Pacific Islands (such as Guam) or who have an unspecified percentage of Asian ancestry. Hispanics are people who have Spanish surnames or who grew up speaking Spanish, regardless of ancestry or skin color. Each of the four groups includes many individuals who are indistinguishable from non-Hispanic whites, but for administrative purposes, they all belong to official, legally protected minorities.

From 1800 to 1900, the proportion of such minorities in the population fell from about 20 percent to 13 percent. In 1900, minorities were predominantly black, with a thin scattering of reservation Indians, Chinese and Japanese in California, and people of Mexican descent in the Southwest. From 1900 to 1950, the relative size of the minority population remained about the same.

Thereafter, immigration created an entirely new situation. From 1950 to 2000, the Asian proportion of the American population rose about twentyfold and the Hispanic proportion about tenfold. The American Indian proportion tripled, not because of immigration or increased fertility, but rather because of increased self-identification. As a result of political activism and fuller recognition of Indian treaty rights by the federal courts, American Indian ethnicity acquired much greater prestige. After 1970, more people of full or mixed tribal descent described themselves as American Indian. In 2000, an estimated 28 percent of Americans belonged to an official, legally protected minority group.

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