In 1978, more than 3,500 letters written over a thirty-year friendship between Eleanor Roosevelt and Lorena Hickok were discovered by archivists. Although the most explicit letters had been burned (Lorena told Eleanor's daughter, "Your mother wasn't always so very discreet in her letters to me"), the find was still electrifying enough to create controversy about the nature of the women's relationship. Historian Rodger Streitmatter has transcribed and annotated more than 300 of those letters—published here for the first time—and put them within the context of the lives of these two extraordinary women, allowing us to understand the role of this remarkable friendship in Roosevelt's transformation into a crusading First Lady.