I don't know about breeding them from scratch in captivity, but I can say from personal experience that they will lay eggs in captivity, and the eggs can be hatched. I had a w/c a couple years ago that dropped 5 eggs, all of which hatched successfully. Didn't even know she was gravid at the time!
They're fairly common around here (central OK), but the buggers are virtually impossible to spot unless they happen to be crossing a vegetation-free area.
They are, of course, one of the most utterly docile species of snakes around. But the down sides, captivity-wise, are that they tend to be nervous (might dart out of the container the moment the lid is removed), and from what I've seen, they usually don't eat well in captivity.
MichaelB