http://geography.about.com/od/obtainpopulationdata/a/uspop.htm
US Population through History
The Growth of the Population in the United States
by Matt Rosenberg
Take a look at how the population has changed since the 1790 to the year 2000.
How has the population in America changed over time?
When was the biggest increase in one decade? Why do you think it occured?
Is the population increasing or decreasing? Why?
Did the population ever decrease in the span of a decade? If so, why?