What is a critical appreciation of The Portrait of a Lady by Henry James?

This novel by Henry James is an outstanding achievement for the way it focuses on a central character and locates her within a tightly structured narrative that does not seem contrived. Although James is a meticulous wordsmith, he uses language in service of the novel as a whole rather than to show off his talent. It is Isabel Archer who sustains the reader’s attention, not Henry James. Isabel is believable and memorable because James shows that her dilemma is consistent with her personality: it is Isabel’s innate goodness, not an innocence or naïveté that can be altered by experience, that makes her trust those who do not always have her best interests at heart. Similarly, the character of Gilbert Osmond seems irredeemably corrupt, but he is not a cartoon villain. Isabel does grow and develop through her experiences, but her shock upon learning how dreadfully she has been manipulated confirms the quality of her character.
While the novel is primarily a study of the characters’ interactions, it also stands out as a social commentary entirely suited to its time. The complicated relationships between Americans and Europeans, including the clash between materialism and culture, factor into Isabel’s opportunities and her decisions. James deftly handles the various plot lines an apparently promotes faith in the power of love; by not forcing an incongruous happy ending, he makes the novel’s resolution believable as Isabel confronts the extent of her loss.

The Portrait of a Lady by American author Henry James, published in 1881, is a highly regarded novel that explores the interactions between Americans and Europeans at the end of the nineteenth century.  Its protagonist, Isabel Archer, becomes an heiress and is victimized by a series of unscrupulous men and women on both sides of the Atlantic.  She yearns for independence but nonetheless chooses a traditional role that ultimately does not bring her much happiness.  
Critics laud Henry's work generally and this novel in particular because it captures the tensions between social classes in the new world and the old and because of the psychological depth of its characters.  Isabel's characterization is realistic; she is entirely human and embodies the contradictions present in all of us. She makes life-altering mistakes and ruinous decisions, yet lives out her life with dignity and insists on finding her own way through life, imperfectly as that is.