The most cheerful possibility is "The Big Rock Candy Mountain".

Tinkers and gypsies were homeless, although maybe not in the sense you're thinking about.

There's also Stephen Foster--"Old Folks at Home" definitely fits, and maybe "My Old Kentucky Home". Performing them in the context of modern homelessness would change the whole effect (although, to try to avoid the debate we had, they're obviously not authentic expressions of the feelings of actual uprooted slaves or free blacks).