Mary Nicholson is also claimed by many in the family to have come from Ireland, and she may well have. Her mother's maiden name is claimed to have been Erwin or Irvin. There is a Nicholson Run and Nicholson Island still in Armstrong County, which would be a likely place for her parents to have settled very early, wherever they were from.
A great-grandson, Frank Dumm, in later years wrote about his grandfather, James, going to visit some Nicholson cousins in the Steubenville, OH, vicinity. Perhaps some year some definite connections will be made.
From "The Minteers As I Have Known Them":
"Two of the cousins (Nicholson nieces of Grandmother's) visited from Steubenville, Ohio about the time my father and mother were married, probably in the late eighteen fifties. Mother said they were beautifully dressed in silks but rather formal in their manner. Uncle James and Aunt Jennie Smith visited them later at their home and reported them as being quite wealthy and the owners of Nicholson Brick Company. Mary Nicholson had blue eyes and, as Uncle James always said when speaking of his mother, "she had the 'purtiest' red hair".
Mary Nicholson Minteer's mother was an Erwin or Ervin and there were brothers and sisters, but the only name I ever heard was McCormick. I never heard of any visiting between them, but I believe the Nicholson and Erwin families continued to live in Venango County."