Mary Therese McCarthy was born on June 21, 1912, in Seattle, Washington to Roy McCarthy and Therese (Tess) Preston McCarthy. She was of mixed religious origins from her Irish Catholic father and her half-Jewish/half-Protestant mother, which in part shaped the marginalized identity she depicts in her autobiography, Memories of a Catholic Girlhood (1957). McCarthy’s parents died in the influenza of 1918 en route to Minneapolis, leaving Mary (age 6) and her younger brothers Kevin (4), Preston (3), and Sheridan (1) orphaned at a young age. The McCarthy children were raised by what she characterizes as her austere and harsh guardians, their great-Aunt Margaret Sheridan and her husband, Myers Shriver, in a modest home in Minneapolis.
McCarthy chronicles these early years of denial and deprivation in her autobiography, Memories of a Catholic Girlhood, and describes being “saved” by her maternal grandparents, the prominent Seattle lawyer Harold Preston and her genteel Jewish grandmother, Augusta Morganstern Preston, who brought Mary to their home in Seattle, Washington while her younger brothers went off to boarding school. In her later autobiography, How I Grew (1987) McCarthy describes the intellectual awakening she experience in Seattle, which began by reading works by Dickens, Tolstoy and Dumas among others in her grandfather’s library and through the public library.
McCarthy enrolled in the Sacred Heart Convent, where she describes having a crisis of faith in Memories of a Catholic Girlhood, then briefly attended Garfield public school where she was introduced to a more bohemian outlook and democratizing influence, and was finally schooled at the Annie Wright Seminary, where she was mentored by a Vassar graduate, Dorothy Atkinson, who encouraged her to go East to Vassar for college.