Jack Treacher tells Bridget that his mother died in the Peshtigo fire of 1871. Peshtigo, Wisconsin, is in in Marinette County in the northeast part of the state (above what is called the 'junction of the hand', or where your thumb and pointer finger join together - Pestigo (pronounced Pesh' tih- go) would close to the tip of the pointer finger) just shy of the Upper Michigan Peninsula border. The 1871 fire is considered the most deadly wildfires in American history, and probably in all recorded history, even through 2022, burning 1.2 million acres of land, and estimating deaths between 1500 and 2000 people. It occurred the same day as the Chicago Fire, which though much more famous, only resulted in about 300 deaths overall and just over 2100 acres of land burned - though, Chicago's fire burned mostly urban buildings verses Peshtigo's mostly forested land areas. The remains of hundreds of Peshtigo residents are buried in the city's cemetery, so it is not unreasonably that Jack's father would have not been able to bring his wife's body back to New York and thus why he buried an empty casket full of her personal belongings and stones for weight.
The quadrille ball for the debutantes was filmed at The Breakers mansion in Newport, Rhode Island.
The mansion used for the Astor's summer home is Chateau-sur-Mer in Newport, Rhode Island.
Title was spoken by Ward McCallister toward the end of the previous episode, "Irresistible Change," referencing why his wife was not part of the carriage party to watch the lighting of the Times Building.