This is going to be a hard book for me to rate. It's very technical and took me almost the whole month to get through. But, the story it told was an important one. I consider myself educated and this was a story I was completely clueless about. Not anymore. Dorothy, Katherine, Mary, and Christine's stories are out there now. Hopefully, more people will read this book and educate themselves. Hopefully, each gets their own biography since there is (I think) much more to learn about them as individuals.