Mr. Nathans is brilliant at reconstructing Mary Walker's life and her relationship with Peter and Susan Lesley.

WSJ: Book Review: To Free a Family

Since only three letters from Walker have been found, she comes alive through Peter and Susan's letters and their family papers, as well as through the Cameron family papers and the archives of Boston abolitionists.

WSJ: Book Review: To Free a Family

In Boston, Walker lived with James Lesley's cousin, Peter Lesley, and his wife, Susan.

WSJ: Book Review: To Free a Family