Wow!Thanks for the wedding date.Also I did not know about the daughter who died--that is very helpful.
Here is what I have found on the various searches I have done and it may not be entirely correct, but I have been working with this information.
Cyrus Elder born Somerset PA on June 16, 1833.I do not have his parents' names.This comes from the Encyclopedia of American Biography.
Nancy Jane Swank was born May 31, 1840, the daughter of George W. Swank and Nancy Moore.I have place of birth as Johnstown, but I am not sure that is right.Nancy had at least one sibling, the George Swank who was the editor of the Johnstown "Tribune" at the time of the Flood (1889).He watched the entire deluge from his upper story window on Clinton Street (the Tribune building did not crumble in the Flood).
The 1870 Census lists their children as:George (age 8, so born in 1862), Nanie (given name, Nancy Moore Elder, also known as Nannie and Moor in some listings) age 4 so born in 1866; and J. C. (no indication of name or sex) age 5 months (so born in 1869 or perhaps 1870).Another source listed a son William born in 1879.(There also may have been a Cyrus Elder Jr, since one of the genealogy sources lists Cyrus as "Cyrus Elder Sr.")
David McCullough's account of the Johnstown Flood chronicles this family very closely.Cyrus arrived home on the day express that morning at 10:15, and could not get home because of the early flooding of the town--he saw his wife and daughter Nanie waving to him from his Walnut street home.He hired first a horse and then a wagon to try to get through the flooded streets, but both proved impractical, so he went instead to Nancy's brother's home "uptown" which is what saved him.When the deluge from the South Fork dam hit the city, the Elder home was swept away, along with Nancy and Nanie--it was Nancy's 49th birthday.Neither body was identified as having been recovered.
Cyrus was the chief counsel for the Cambria Iron Co. and one of the city fathers--he later gave the centennial address to the city in 1900.He published a book "Poems" in 1909.He was also a PA tax law expert.