Alva is a young woman from an old money Southern family whose wealth vanished following the Civil War. Faced with her family's impending destitution, she focuses on securing a marriage of convenience to a wealthy suitor. She possesses a keen mind and a strong interest in architecture. She also harbors a deep desire to use her privilege for progressive causes, but she feels constrained by the rigid rules of late 19th-century New York high society.

William is the wealthy heir to the Vanderbilt industrial fortune. As a new money figure, he seeks a respectable marriage to elevate his family's social standing among the New York elite. He lives a life of immense privilege and leisure, dedicating his time and fortune to building yachts and racing horses. He spends months traveling rather than attending to his wife's intellectual or emotional needs.

Consuelo Yznaga, who becomes Lady C upon her marriage to a future British duke, is Alva's worldly and confident best friend. Hailing from a wealthy family with Cuban sugar plantations, she moves through elite society with ease and assertiveness. She provides a sharp contrast to Alva's initial naivete, adopting bold habits like smoking in public and speaking frankly about the practical realities of sex and marriage.

Oliver is the handsome, thoughtful heir to the Belmont banking fortune. Unlike many men in his social circle, he shows a genuine interest in progressive politics and history. He treats Alva as an intellectual equal, listening carefully to her ideas and offering a striking alternative to the superficial conversations typical of Gilded Age dinner parties.

A Southern gentleman and influential socialite, Ward acts as the central gatekeeper and arbiter of New York high society. He guides new money families and anxious brides through the complex rules of social etiquette. He provides crucial assistance and practical advice. He even provides temporary funding to Alva when she is struggling to secure her marriage to William.

Alva and William's eldest child and only daughter. Raised in immense wealth and carefully managed by her mother, she grows into a beautiful and well-educated young woman who speaks multiple languages. She often finds herself at odds with her mother's strict plans for her future and social placement.

William's grandfather and the patriarch of the Vanderbilt family. He is a self-made industrial tycoon who built his immense fortune in shipping and railroads. Despite his staggering wealth, the traditional New York elite look down upon him as nouveau riche and a war profiteer, driving his family's desperate desire to marry into established social circles.

William's sister-in-law, married to his brother Corneil. She represents the rigid, conservative side of high society, frequently displaying a judgmental attitude. She strictly adheres to the social expectations of the era and actively voices her disapproval of progressive or unconventional choices, such as Alva hiring a Black lady's maid.

William's brother and Alice's husband. He is deeply involved in the family's financial legacy and social standing. He frequently aligns with his wife's traditional views and works alongside the other Vanderbilt men to manage their extensive inheritance and properties.

The daughter of a housemaid who becomes Alva's personal lady's maid. She is intelligent and talented. She proves highly skilled in her work, becoming a steady presence in Alva's daily life despite the pervasive racism she faces from members of the Vanderbilt family.

The undisputed queen of New York high society. She strictly controls who is accepted into the elite circle, wielding immense power over the city's social life. Winning her approval is the ultimate goal for the Vanderbilts as they attempt to legitimize their immense wealth through social acceptance.

A prominent architect who collaborates with Alva on ambitious building projects. He recognizes her natural affinity for architecture and design, working closely with her to create stunning mansions that will cement the Vanderbilt family's physical and social presence in New York.

Alva's older sister. Like Alva, she feels the intense pressure of their family's financial ruin following the Civil War. She attempts to guide her younger sister through the practical realities of marriage and societal expectations, advising her to prioritize sense and survival over romance.

William's father and the Commodore's son. He manages the transition of the family's vast wealth between generations. He is highly supportive of Alva's ambitious plans to build enormous mansions, recognizing her strategy to secure the family's social standing.

William's mother, a friendly woman with distant connections to the Roosevelt family. She helps welcome Alva into the fold, organizing living arrangements and offering a gentler presence compared to the harsh social judgments found elsewhere in elite circles.

Alva and William's second child and first son. He is born into staggering wealth and privilege, growing up in the various grand mansions his mother designs across New York and Rhode Island.

Alva and William's youngest child. As a young boy, he frequently misses his father, who spends months away in Europe overseeing the construction of new yachts.

A handsome, 31-year-old bachelor who courts the teenage Consuelo Vanderbilt. He has a reputation as a wealthy playboy with a history of womanizing, which deeply concerns Alva as she attempts to manage her daughter's social prospects and secure a stable match.

William's youngest brother. He is an unmarried man who devotes himself to running the family farm on Staten Island and caring for their mother. He harbors highly ambitious architectural dreams of his own, eventually announcing plans to build an enormous estate in North Carolina.