Hrm. I'm not really sure what to make of this book. It's a pretty good read with a reasonably compelling narrator, but plot doesn't quite gel. The ending left me mystified, and not in that cool dazed way where you contemplate what might happen next. Instead we're left with what essentially feels like a "to be continued," which I would have thought the author would be too classy for.
Anyway, Genna is a smart and solitary African- and Panamanian-American teenager growing up in early 21st century Brooklyn who gets transported back in time to more or less the same location, just before Christmas in 1862. She ends up working for a white doctor as nursemaid to his child and as a sort of nurse-in-training in his practice. (She wants to become a doctor, a psychiatrist specifically, a notion Dr. Brant thinks is absurd. Negroes' heads are small than white peoples', so they aren't capable of being as smart. Same with women vs. men.) She has two potential love interests, one from the present, and one from the future/past, who manages to find her in the 19th century.