The poverty rate in the United States today is roughly 13%. This means that roughly 40 million Americans live in poverty.
To give you some idea as to what poverty means, a family of two parents and two kids is in poverty if it makes less than about $22,000 per year. So the poverty line is pretty low.
For non-Hispanic whites, the percent in poverty was a bit under 9. About 13% of Asians were in poverty, 23% of Hispanics and 24% of African Americans were poor. All of these numbers are for 2008, the last year for which data are available.
28% of households with a woman and no husband are in poverty, 13% of those with a man and no wife. 5% of married couple households are in poverty.
The link below will at least give you information for age as well.