As the title indicates, the novel chronicles Silas Lapham’s ascent, in wealth and status. It also traces his fall. Lapham, his wife, and their two daughters benefit from his riches as the family from rural Vermont adapts to metropolitan Boston. In doing so, they adopt the exterior trappings and, to some extent, the interior attitudes of the upper class. When Lapham loses his fortune, however, the family likewise must adapt to their reduced circumstances. Penelope, the older daughter, seems to be a nonconformist through much of the novel but it is possible that her attitudes were a phase or even a posture.
Penelope can be interpreted a nonconformist in the sense of embodying the modern or new woman, as understood in the late 19th century. Along with her mother and sister, she utilizes the family’s resources primarily to live a life of leisure. While upper-class girls often took up accomplishments such as music or embroidery, the Lapham girls prefer indolence. Penelope, not interested in fashion or flirtation, enjoys reading.
In Chapter 7, Penelope is said to be reading George Eliot’s Middlemarch, and getting books from the library—not something the other family members do. Tom, who works in her father’s business, is from a prominent but financially troubled Boston family, the Coreys. His mother disapproves of the Laphams as new money people, and criticizes them for borrowing rather than buying books. In this sense, the whole family does not fully fit in to Boston society, and Pen is exceptional in large part because of personal qualities Tom notices. As that type of behavior was not completely out of the ordinary for upper-class girls of the day, however, she might be considered as conforming to a specific set of trends.
At the novel ends (Chapter 27), she embarks on an apparently conventional path, as she marries Tom. Yet this courtship has its twists and turns; her sister is interested in Tom, and Penelope also claims she does not want Tom to be burdened with a poor wife. After he convinces her that this is not an obstacle in his mind, she consents to the match. Since his business ventures will take him to Mexico, she might have further opportunities to resist social conformity—and in any event, she says, she won’t find it harder to fit in among Mexicans than with his proper family.