Do Fans of Historical TV Shows Favor a Particular Time Period?

“The Gilded Age,” Julian Fellowes’ critically lauded follow-up to “Downton Abbey,” has returned for a second season on HBO. Although “The Gilded Age” slightly alters the formula that made “Downton Abbey” so popular, swapping out turn-of-the-century England for a rapidly developing America in the late 1800s, it takes place just a few decades before its predecessor. Does that just reflect Fellowes’ fascination with a particular period? Or should we take it as a sign from a master of the genre that this is the ideal setting for a period piece TV show?