Immigration, legal and illegal, fuels a growth spurt that finds U.S. with population of 300 million

October 12, 2006

The United States is the planet's third most populous nation and is in the middle of a growth spurt fueled by immigration. Clicking upward at a rate of one person every 11 seconds, the nation’s population officially surpassed 300 million in mid-October.

Some demographers say this continued growth is essential to support an aging population in retirement and a sign of the continued allure of the United States even at a time when its image around the world has been sullied by the war in Iraq.

When the U.S. population surpassed 200 million on a census clock in 1967, cheers rang through the lobby of the Commerce Department, and applause interrupted President Lyndon B. Johnson's celebratory speech.

Forty years later, however, 300 million was greeted more with hand-wringing ambivalence than chest-thumping pride. Demographers were saying the odds were good that the 300 millionth American would be a Hispanic boy born in Los Angeles.

'At 300 million, we are beginning to be crushed under the weight of our own quality-of-life degradation,' 'said Dowell Myers, a professor of urban planning and demography at the University of Southern California.

The fact that U.S. population growth is fueled in large measure by immigrants and their children causes anxiety and increasingly worries native-born Americans and politicians, especially three weeks before an election. Immigrants, legal and illegal, account for about 40 percent of the population growth. Hispanics from Latin America, by far the largest share of recent immigrants, are driving the natural increase here. On average, Hispanic women have one more child than non-Hispanic white women.

At a time when about half the 1.5 million immigrants entering the United States are illegal, the Bush administration is not eager to call attention to America’s out-of-control borders. Many conservatives believe that unbridled immigration threatens to ruin the country.

Three hundred million is also a discomfiting reminder of a nation that, on its east and west coasts, at least, is running noticeably low on elbow room. There is more traffic, more sprawl, more rules against growth, more protests against anti-growth rules, and more of the greenhouse gas emissions that cause global warming. A surging population in the Southwest is straining the supply of water.

'We are not the wide-open spaces anymore,' said Martha Farnsworth Riche, who headed the Census Bureau in the mid-1990s and is now a research demographer at Cornell University. 'Our choices are constrained.'

In Los Angeles, the nation's most densely populated metropolitan region and its most heavily Latino area, 300 million will be yet another confirmation that congestion is out of control, Myers predicted. 'I don't think people view population growth as a plus anymore,' he said, noting that Angelenos are punished by it 'every single day' when they go out in freeway traffic.

The 300-million milestone is actually an educated guess by the Census Bureau, not an actual people count, generated by a formula that crunches births and new immigrants against deaths.

From the Declaration of Independence in 1776, it took the U.S. 139 years to get to 100 million in 1915, then 52 more years to reach 200 million in 1967 and 39 more years to hit 300 million.  Demographers predict that the 400 million mark will be reached in about 37 years.

A change in immigration law in 1965, when Congress abolished a national-origins quota system, unintentionally reignited immigrant-led population growth, making family reunification an important criteria for immigration and it leading to a chain reaction of higher fertility.

Immigrants now account for about 12 percent of the total population, more than double what the portion when the population topped 200 million. Immigrants are also more visible, having fanned out from gateway cities to parts of the rural South and Midwest where they had not been seen in substantial numbers before.