'There were 72.5 million children in the United States in 2022, which was 0.4 million less than in 2021. The total number of children is projected to increase to 78.2 million in 2050. In 2022 (the latest year of data available at the time of publication), there were fewer children in the 0–5 age group (22.4 million) than in the 6–11 age group (24.2 million) or the 12–17 age group (25.8 million).

"Since the mid-1960s, children have decreased as a proportion of the total U.S. population. In 2022, children made up 22% of the population, down from a peak of 36% at the end of the Baby Boom, in 1964. Children’s share of the population is projected to continue its slow decline through 2050, when children are projected to make up 20% of the population.

"Racial and ethnic diversity has grown dramatically in the United States in the last 3 decades. This growth was first evident among children. In 2022, 49% of U.S. children were White, non-Hispanic; 26% were Hispanic; 14% were Black, non-Hispanic; 6% were Asian, non-Hispanic; and 6% were non-Hispanic “All other races.”

"This population is projected to become even more diverse in the decades to come. Whereas the percentages of children in most of the other racial and ethnic origin groups have declined, the percentage of children who are Hispanic has grown substantially, increasing from 9% of the child population in 1980 to 26% in 2022. In 2030, less than half of all children are projected to be White, non-Hispanic. By 2050, it is projected that 39% of all children will be White, non-Hispanic; 31% will be Hispanic; 14% will be Black, non-Hispanic; 7% will be Asian, non-Hispanic; and 9% will be non-Hispanic 'All other races.'"

Source

Federal Interagency Forum on Child and Family Statistics. (2023). America’s children: Key national indicators of well-being, 2023. Washington, DC: U.S. Government Printing Office.