As a writer Caldwell was praised for her intricately plotted and suspenseful stories, which depicted family tensions and the development of the U.S. from an agrarian society into the leading industrial state of the world. Caldwell's heroes are self-made men of pronounced ethnic background, such as the German immigrants in "The Strong City" (1942) and "The Balance Wheel" (1951). Her themes are ethnic, religious and personal intolerance ("The Wide House", 1945), the failure of parental discipline ("Let Love Come Last", 1949) and the conflict between the desire for power and money and the human values of love and sense of family ("Melissa" (1948), "A Prologue to Love" (1962), and "Bright Flows the River" (1978)).