Addams would enjoy the Presbyterian Cemetery on Mountain Avenue in Westfield as a child, where – according to author and Addams expert Ron MacCloskey – he would wonder what it was like to be dead.[5] In the cartoons, his ghoulish creations lived on Cemetery Ridge with a dreadful view.
A house on Elm Street and another on Dudley Avenue – into which police once caught him breaking and entering – are said to be the inspiration for the Addams Family mansion in his cartoons. College Hall, the oldest building on the current campus of the University of Pennsylvania, where Addams studied, was also an inspiration for the mansion.[6] One friend said of him: "His sense of humor was a little different from everybody else's." He was also artistically inclined, "drawing with a happy vengeance", according to a biographer.[3]
https://en.wikipedia.org/wiki/Charles_Addams
Original Morticia from her grave (his first wife):
https://www.findagrave.com/memorial/208438556/barbara-jean-hersey
Original model pack by Charles Addams: https://archive.org/details/adamsfamilymodelpack/page/n49/mode/2up
From your link the caption was
"It's the children, darling, back from camp."
I….did not even see or read the text. I suck.