"Of the Nation's 72.3 million minor children in 1999, 2.1% had a parent in State or Federal prison. Black children (7.0%) were nearly 9 times more likely to have a parent in prison than white children (0.8%). Hispanic children (2.6%) were 3 times as likely as white children to have an inmate parent."
Source
Mumola, Christopher J., US Department of Justice Bureau of Justice Statistics, Incarcerated Parents and Their Children (Washington, DC: US Department of Justice, August 2000), p. 2.