This paper explores the nation's changing child population based on data from the 2010 census. While the number of U.S. children increased only slightly, the demographic shifts within the population were considerable. Some areas of the country (Nevada and Texas) and some demographic groups (including children of mixed race) grew significantly, while the number of children in other areas (Vermont and New York) and in other groups (such as non-Hispanic whites) declined. Appended are: (1) State Changes in Child Population 1990, 2000, and 2010; and (2) Distribution of Children (under age 18) by Race and Hispanic Origin: 2010. (Contains 16 tables, 3 figures, 1 chart and 30 endnotes.)