Thanks all for so much effort and input. I've got multiple issues to respond to so let's get to the big one first.
Does this discussion belong on this board? I began this effort with the goal of taking what I knew about Stephensons in Fairmount (a section of Philadelphia just north of the Art Museum and west of the prison and tracing back first to Newcastle West and then to Newcastle upon Tyne. If the administration of the site puts my initial inquiry on the US board, so be it. What happens when my/our (because I don't think I'll make it without you) efforts are rewarded and the effort moves to Ireland. Is that a new topic there? But I'm happy with whatever the experts decide is correct.
Moving on to your various replies:
Reply # 35: Yes, it is tempting. The dates of birth of John and Mary do not match what I understand to be the case. I have JPS' DOB as 1852. I have located a Mary Spearing also born in 1982, who lived in the 18th Ward. Family oral history has it that Mary Spearing came from West Philadelphia, i.e., the other side of the Schuylkill River, and was the daughter of a doctor. Her mother would not speak to JPS and her parents did not come to the wedding. That location and her age are reasonable matches but I will know more when I see the Cathedral Cemetery records.
Reply # 37: I think this is correct. Attached please see the 1940 US census entry for Richard, his mother Ellen and his brother Joseph. I remember Aunt Nellie and went to her funeral. Her daughter stayed in the house. The nesting of the three households makes this a solid lead. It also confirms Richard's DOB as 1872-1873.
Reply # 41: I would be surprised if the 1870 Olive Street family is related. The address is on the far eastern end of the ward and Eastern State Prison, a massive edifice, cuts that part of the ward off. Also, the 2521 Olive Street address is so much closer to where the Stephensons clustered and Mary Stephenson is not that far off in age from what's expected. It's important to remember that most people in Fairmount at that time rented their homes. JPS' son John P Stephenson bought 2518 Meredith Street, which is right around the corner from the Aspen Street addresses (going west) and right around the corner from the Olive Street address (going east). I suspect that JPS and Mary rented 2521 Olive until her death in 1908 and then JPS moved in with his son John.
Reply # 42: Another solid fact is that JPS died in 1917. My father, who was age 5, remembers going to see him shortly before he died and then to the funeral. It was his first viewing (in the parlor) and he never forgot it. As an aside, he was living with his son John then, in a rented house four doors down the street from 2518 Meredith.
I hope these responses help. I apologize for the length but there was a lot to cover. I hope to be able to provide some hard facts later this week after I finish reviewing cemetery and city records.
Again, thanks to you all for your generous and gracious help.
Mark