56572: Life on the edge of the frontier

The population of the United States reached 300 million on October 17, 2006, said the U.S. Census Bureau. With one birth every 7 seconds, a death every 13 seconds, and a migrant entering the country every 31 seconds, the United States’ population is growing at a rate of one person every 11 seconds. Where are all of these people living? This map charts out the number of people in every square kilometer of the United States.

Photo montage by NASA