Creator Julian Fellowes has said that he hopes to have a younger version of the Countess of Grantham, originally played by Elizabeth McGovern in Downton Abbey (2010), appear in the show at some point.
In a January 2022 New York Times article, Dave Itzkoff reports that by the end of the shoot Carrie Coon (who plays Bertha Russell) was eight months pregnant. Coon said, "There was a point where I couldn't wear a corset anymore. You'll see some cleverly-timed horses and some hand acting to hide my stomach."
Creator Julian Fellowes revealed on HBO's official podcast for the show that George Russell is based on real-life robber-baron and railroad financier Jay Gould. Like the Russels, the Goulds struggled to gain acceptance among New York's old money elite, especially by de facto leader Mrs. Astor.
As a historical period, the Gilded Age spanned, roughly, from 1865 (the end of the Civil War) or 1870 to about 1900. The term comes from the title of an 1873 novel by Mark Twain and Charles Dudley Warner, "The Gilded Age: A Tale of Today," but it was not used to describe the era until historians and progressive reformers adopted it in the 1920s as a way to disparage what they saw as the period's contradictions and hypocrisies: its simultaneous hyperbolic excesses and extreme poverty.
In January 2022, the New York Times's Dave Itzkoff reported that filming took place largely on sets constructed on soundstages on Long Island, though some scenes were shot on location in Troy, New York, Newport, Rhode Island, and the Museum of American Armor in Old Bethpage, New York.