When Emily Post's Etiquette was published in 1922, reviewers already considered it hopelessly behind the times, yet its gentle instruction, the product of a 50-year-old grandmother, continues to find a huge audience. In Emily Post: Daughter Of The Gilded Age, Mistress Of American Manners—the first major biography of Post—Laura Claridge argues that Post acted as a sociocultural bridge, adapting the lessons of her upbringing—in which genteel New York was forced to accept "new money" names into high society—to the Jazz Age and beyond.

Post crafted her persona in the wake of her success to make it seem accidental, but she never spoke about the incident in her life when she might have found the world most unmannered. The daughter of an architect and a coal heiress from Baltimore, Emily Price married young to banker Edwin Post, an aggressive social climber whose nights out on the town resulted in a blackmailing attempt by publisher William D'Alton Mann over an affair in 1905. Rather than quietly paying Mann off, Edwin decided to fight him, bringing justice to the class he targeted, at the cost of splashing the lurid details of the Posts' marriage over the tabloids. Claridge finds no evidence that Edwin consulted Emily before deciding to take this route—a breach of etiquette that humiliated the faithful, guileless wife and led to her marriage's dissolution.

In Claridge's view, Post "had needs that a Gilded Age society marriage could not accommodate"; though she never wanted it, the divorce, itself a modern invention, freed her to develop herself in a way her conventional upbringing would never have warranted. She never considered herself a feminist, but Post's crafting of her own career, from her early days writing Edith Wharton-esque society novels to her later mastery of endorsement deals and radio spots, shows she was remarkably adaptive to the changing times which enabled her to essentially market her upbringing. Claridge alternates between novelistic depictions of watershed moments in Post's life and deft scene-setting placing her in her upper-class milieu, but her biggest asset is Post's own words from her many media appearances after Etiquette's success. While she may have wanted to depict her own success as accidental, she built her reputation for expertise as assiduously as her father picked up architectural commissions, and the context Claridge brings to her public image bolsters her case for Post as a woman who thrived amid the complications of modernity even as, for many readers, she embodied the establishment.