After a while of living in a shelter you get on each other's nerves. You, like, go crazy, from being so close together all the time. We been here at this shelter almost two years now. There's four of us living in one hotel-size room. There used to be five, but my brother run away last month. We're lookin' for him, but I can tell you he'll never come back here to live. Why would you? I'll probably leave myself when I'm 15—if I'm not too scared.

TWELVE-YEAR-OLD Shaun is one of the 350,000 Americans who the government estimates sleeps in homeless shelters each night. More than half of these people are children and their families. The poorest are those who live in a single-parent family headed by the mother. Living in a shelter is better than sleeping...