NYC Municipal Archives
The archives for New York City, includes the vital records of birth, death and marriage, which you can walk out with a copy, paying $11 (online is $15?).
It is a beautiful building, next to the city hall, in the style of Paris Opera, the Palais Garnier, with intricate skylight and beautiful doors and windows. Have dinner at Coco Bistro and drinks at the Oyster House on Pier A @ Battery Park.