"The Age of Innocence" centers on an upper-class couple's impending marriage, and the introduction of the bride's cousin, plagued by scandal, whose presence threatens their happiness. The story is set in the 1870s, in upper-class, "Gilded-Age" New York City. The novel is noted for attention to detail and its accurate portrayal of how the 19th-century East Coast American upper class lived, as well as for the social tragedy of its plot.

"Old New York" is a collection of four novellas revolving around upper-class New York City society in the 1840s, 1850s, 1860s, and 1870s. The New York of these stories is the same as the New York of The Age of Innocence, from which several fictional characters have spilled over into these stories. The observation of the manners and morals of 19th century New York upper-class society is directly reminiscent of The Age of Innocence, but these novellas are shaped more as character studies.