Criticism has long recognized that, in its amplitude of conception and fineness of execution, The Portrait of a Lady marks a decisive turning point in the history of Henry James's early career. In this novel many of the themes and motifs that had slowly evolved in the author's previous work resurface with particular intensity: the probing contrast of transatlantic manners and mores (evident at least as early as ‘A Passionate Pilgrim’ (1871)), the distinctive moral spontaneity of the American heroine (more notoriously embodied in the eponymous ‘Daisy Miller’ (1878)), the deliberate concentration of psychological interest in the novel's central consciousness (first attempted, manifestly, in Roderick Hudson (1875)). If, as Emerson famously said of Whitman's Leaves of Grass as published in 1855, the work ‘must have had a long foreground somewhere’, the foreground of The Portrait of a Lady can be discerned, at least in part, in many of James's earlier (and less celebrated) experiments in fiction.

There is a range of more specific rehearsals revisited by James – and significantly embellished or elaborated – when he composed The Portrait of a Lady. Bessie Alden's rebuff of Lord Lambeth in ‘An International Episode’ (1879) prepares us for Isabel's refusal of Lord Warburton. In ‘Longstaff's Marriage’ (1879), Diana Belfield's rather stiffly ingrained chastity prompts her to spurn several offers of marriage (she is ‘passionately single, fiercely virginal’: ‘it was not her suitors in themselves that she contemned; it was simply the idea of marrying’) until at last she relents – in Rome: Isabel, too, feels it is ‘vulgar’ to dwell excessively on the subject of possible husbands, and the same pattern of deferred courtship is repeated in the later novel. Matters which eventually surface in Portrait – concealed illegitimacy and vengeful maternity – drive the plot of Roderick Hudson (1875), which also takes place largely among Americans in Italy. Claire de Cintré's capitulation to family authority and retreat to the convent frustrate Christopher Newman's marital designs in The American (1877), foreshadowing Rosier's defeat in an important sub-plot of the later work, when Osmond obliges Pansy to resume her parochial confinement with the Catholic sisterhood.