The number of people in the U.S. who were in poverty in 2005:

38,231,521

The percentage of those people who were children:

36%

The estimated number of people in the U.S. who are homeless for any period of time in a given year:

3.5 million

The number of people who were homeless in a night in October 1996:

444,000

The number of people who were homeless in a night in February 1996:

842,000

Percentage of homeless that have been homeless for less than two years:

70%

Percentage of homeless that have been homeless for less than six months:

40%

Percentage of homeless that live in vehicles:

59.2%

That live in makeshift housing (tents, cardboard boxes, etc):

24.6%

Percentage of homeless that live in the same city in which they became homeless:

75%

Percentage of homeless people that are employed:

13%

Estimated percentage of homeless diagnosed with a mental illness:

16-22%

Percentage of the overall U.S. population diagnosed with a mental illness sometime in their lives:

40%

Estimated percentage of homeless that are substance abusers:

26-40%

Percentage of homeless men that are veterans:

40%

Percentage of U.S. cities whose estimated homeless population is much greater than number of beds in emergency shelters:

100%

Percentage of homeless who are single men:

51%

Families with children:

30%

Single women:

17%

Likelihood to have a personal or property crime committed by a homeless person than by a housed person:

10% less likely

Percentage of homeless people that receive Social Security or General Assistance (food stamps):

20%

Percentage of homeless that report having no health insurance:

55%

Percentage of the general U.S. population that reports having no health insurance:

16%

Average amount a homeless person receives in income a month:

300 dollars

Resources: The National Coalition for the Homeless; National Law Center on Homelessness and Poverty, Homelessness in the United States, Wikipedia.