She was, in the words of former Kirkus editor Barbara Bader--whose American Picturebooks Marcus quotes--"the first to make the writing of picturebooks an art." As founding editor of the innovative William R. Scott children's book line, as well as the author of about 100 picture books during her 15-year career, Brown (1910-52) was also, as Marcus (who reviews children's books for Parenting Magazine) sums up, as responsible as anyone for making the field of children's picture books "a vital creative enterprise in her time." Brown's two enduring classics, The Runaway Bunny (inspired by a medieval ProvenÃ‡al love ballad) and the "hypnotic" Goodnight Moon (still going strong after 45 years and four million copies), were ignored by The Horn Book and the New York Public Library but helped win her a 1947 celebrity profile in Life. Marcus recounts how Brown found her calling while an intern at the experimental Bank Street School for child-development study and teacher training--and how, by Bank Street policy, the books she wrote and edited were approved or revised according to the responses of "the threes" or "the fives" (or other appropriate age groups) enrolled at the school. From published reports, Brown's considerable correspondence, and interviews with those who knew her, Marcus pieces together a picture of his subject's doubts and achievements and ambition to write for grown-ups; her offbeat homes and quirky persona; and her friend-filled but lonely life punctuated by a few short affairs and engagements, then an unhappy relationship with a difficult woman who called herself Michael Strange, and, finally, love and imminent marriage to a younger man, Pebbles Rockefeller--only to die after surgery at age 42. If Marcus doesn't bring Brown to scintillating life, he does give an honest and informative account, including intriguing sketches of Bank Street and of developments and personages in the children's book world of the time. And he does it without the sanctimonious reverence so endemic in his field.