The promise of the American Dream is that in our society, anyone can succeed with hard work and persistence. Even in the current economic downturn, the majority of Americans (72 percent) believe that it is possible to start out poor, work hard, and become wealthy. But does this promise hold true for America's children? How common is it for people who spend part of their childhood living in poverty to experience poverty as adults? How does this vary by how much time children spend living in poverty? And does it vary by race? Economic mobility, the ability to move up or down the economic ladder during one's lifetime and across generations, is central to the ideal of the American Dream. But recent research finds that there are limitations to mobility in the United States. For example, one study of families across generations finds that one's economic position is strongly influenced by that of one's parents: 42 percent of children born to parents in the bottom fifth of the economic distribution remain in the bottom as adults and another 23 percent rise only to the second fifth, while 39 percent of children born to parents at the top of the income distribution remain at the top, with another 23 percent moving to the second fifth. This paper focuses on the lower end of the earnings spectrum and highlights findings from a working paper commissioned by the National Center for Children in Poverty (NCCP). In particular, we report how common it is for children to experience poverty throughout the course of childhood – defined as the years from birth to age 15 – and how that relates to the likelihood that they will be poor in young and middle adulthood.