The time (1870) and place (Pittsburgh) are right but I would rather think that your 'Andrew Carnegie II' is not the issue of 'THE' Andrew Carnegie, as you so stated. Usually, a 'I', a 'Junior' and a 'Senior' precede a 'II' and (THE) Andrew Carnegie's father's name was William. Also, there is no officially recognised i.e. legitimate male issue from (THE) Andrew Carnegie. I am related to William Morrison, brother of (THE) Andrew Carnegie's mother Margaret. (THE) Andrew Carnegie only had one child late in life, a daughter, named after his mother Margaret, who he adored. His brother Thomas did have a few children so it is possible that he had a nephew, though I know nothing of that line of descent. My great-great grandfather, Leander (for whom my grandfather was named following Scots custom) was a first cousin of (THE) A.C. and named his first-born Kate Carnegie Morrison, but she did not survive childhood.