Figure 12.17 The growing human population in the United States. A census conducted every 10 years from 1790 to 1910 indicated that the U.S. population was continuing to increase. However, the rate of increase started to decline by 1910. Based on these data, Pearl and Reed predicted that the population would reach a maximum of 197 million people. In reality, the U.S. population has continued to grow.

Data from R. Pearl and L. J. Reed, On the rate of growth of the population of the United States since 1790 and its mathematical representation, Proceedings of the National Academy of Sciences 6 (1920): 275–288; and U.S. Census Bureau (http://2010.census.gov/2010census/data/apportionment-pop-text.php).