> Closest thing's a birth certificate[EDIT: or naturalization papers, of course, for immigrants], I guess, but that's a pain in the ass for anyone who's had a name change (lots of married women, notably) because then they need more documents.

Or a FS-240, Consular Report of Birth Abroad, from the State Department. I was born on a US military base and although I have a birth certificate, the only think I've ever been able to use it for was my REAL ID. I had to use the FS-240 for my passport, SSN, etc.