Well, it's been a bit over a month since my original post, so here's an update.
About 20 or so little bloodroot seedlings germinated in early April in the small plastic container that I'd planted them in last Fall. I waited until late April to transplant them into individual little paper cups. I think perhaps I transplanted them too early in the past, which was why they didn't survive. Anyway, that was several weeks ago, and about a dozen of them are still alive and growing in the little paper cups. Some are in the shade and others are in the sun. So far, they're doing quite well. This is the longest that I've ever been able to keep them alive. In the past they didn't survive the transplanting. Right now, I'm hoping that the squirrels, chipmunks, or rabbits don't eat them ((they've already eaten a few of them). I hope that at least a few of them will survive until they can be planted out in the Fall.