Of course we should know more about the mothers of Malcolm X, Martin Luther King Jr. and James Baldwin. They are the inception, the root and the core. As Malcolm himself put it: “The mother is the first teacher of the child. The message she gives that child, that child gives to the world.”

It’s such an obvious statement that it is hard to understand how Louise Little, Alberta King and Berdis Baldwin are not household names. Portraits of the three mothers are “mostly limited or completely inaccurate,” Anna Malaika Tubbs, a Gates scholar and Ph.D. candidate in sociology at Cambridge University, writes in “The Three Mothers.” They’ve been thoroughly “ignored even though it should have been easy throughout history to see them, to at least wonder about them.” Tubbs aims to correct that erasure by piecing together what she can from the “margins and footnotes” of books, speeches, funeral programs and letters.