400 Million Americans

According to the Census Bureau, the U.S. population supposedly reached 300 million on October 17, 2006. The occasion was marked ambivalently, as commentators seemed unsure whether to celebrate or lament our growing ranks.

The conventional wisdom about America’s increasing population has evolved over time, as ethnic, economic, and environmental concerns have come to dominate and recede from our political consciousness. In the nineteenth century, our growing numbers made this a truly continental nation — but by 1915, when America’s population reached nine digits, there were widespread worries about how immigration had changed the country’s cultural composition. In the 1930s, President Franklin Roosevelt was so troubled by the Depression-era birth slump that he asked the National Resources Committee to investigate the potential economic effects of a shrinking population. The baby boom after World War II erased that worry, and by 1967, when the nation’s official population clock ticked over to 200 million, the cognoscenti had come to fear the devastating ecological and social consequences of global overpopulation. They took the opportunity to call for government action to reduce the birthrate both in America and abroad. “We needn’t look forward to the future with unmitigated gloom,” said one prominent demographer, since governments around the world “have finally got busy with birth control programs and, with improved contraceptive technology, it may be possible to bring about a substantial decline in the birthrate some time in the next two or three decades.”

That decline has come to pass, and birthrates are so low today in many developed countries that population is shrinking. Today’s greatest population worry is once again economic, since long-term economic growth depends upon population growth. Declining birthrates and aging populations are skewing the developed world toward the elderly, leaving ever-fewer productive workers to support ever-more aged retirees. But of course, much more than economic prosperity is at stake. The cultural vitality of the modern West depends upon our ability to sustain and increase our numbers. And the fullest human flourishing depends on generational cords that fray and snap when children become scarce.

In a speech marking the 200 million milestone, President Lyndon Johnson said that the U.S. had, in its first two centuries, affirmatively answered the questions “Shall we be a free nation?” during the American Revolution, “Shall we be one nation?” during the Civil War, and “Shall we be a humane nation?” during the Depression. The challenge facing the next hundred million Americans, he said, was “Shall we be a great nation?” As we look forward to welcoming the 400 millionth American — some time in 2043, the Census Bureau says — American greatness seems threatened by neither overpopulation nor demographic decline. But for Europe and much of Asia, with plummeting birthrates and mass geriatric societies, dreams of greatness seem less relevant than the mere struggle for cultural survival.