Tracking America's Journey

"The United States themselves," wrote Walt Whitman, "are essentially the greatest poem." That epic is rewritten by each generation but also revised every 11 seconds when a new American enters the population. On the eve of what could be a transformational election, we recently recorded the arrival of the 300 millionth American. The proximity of those two events created the perfect moment to launch what TIME expects will be an annual feature called "America by the Numbers," an illustrated look at who we are as a nation--and where we're going. It is TIME 's first cover story told principally through graphics, and was produced by our superb graphics director, Jackson Dykman.

The idea that "demography is destiny," a phrase usually attributed to the 19th century French philosopher Auguste Comte, lies at the foundation of this week's special report. The social, cultural and economic fabric of a nation derives in large part from its population dynamics. For example, we tend to think a country's crime rate results from a complex mix of social factors, and it does. But it often traces mainly to a single population statistic: the number of young men between 15 and 30 years of age, the population cohort that tends to be responsible for the most crime.

A salient point of the special report is that, unlike Europe and Japan, the U.S. is still growing at a healthy clip. The reason we are still growing is that our immigrants and naturalized citizens are the one part of the population with a birth rate that is more than replacing itself. Half of all the population growth in America is occurring among Hispanics. With immigration becoming such a pivotal issue, people need to remember that in a very real sense immigration is what keeps us growing and helps invigorate our society in myriad ways.

New citizens swear to "bear true faith and allegiance" to the Constitution, pledging loyalty to a document written by men who could hardly have imagined a pluralistic democracy of this many people practicing this many faiths and speaking this many languages. The framers wondered whether Americans had enough in common to form a united nation at all--and they were far more homogeneous than we are, and there were only about 4 million of them. It took 100 years to get to 50 million. We reached 100 million in 1915, when the largest segment of the foreign-born population came from Germany. We reached 200 million in 1967, when the largest portion of foreign-born Americans came from Italy. Today that largest segment is from Mexico. We are now less of a melting pot--the great assimilation metaphor of the 1950s--and more of a patchwork quilt, where people retain more of their national heritage within the context of being an American.

And what have we become politically? One of the graphics in this issue's special report beautifully illustrates how we are less a Red and Blue nation than a United States of Purple. I've long believed that political polarization in America is much exaggerated and that the great mass of Americans are pragmatic moderates who tune out the high-decibel battles of the parties and the pundits. I agree with political scientist Morris Fiorina's thesis that as a nation we are closely divided, not deeply divided, and that graphic shows it.