@fbrereto +1 Great!! Really nice. I see the "City of New York" as birth place. Imagine that is their honeymoon voyage, too, so it fits nicely into the whole family story.
Even within the New York city there are several Charles Fosters around that time
If only there was more family information for the Charles in the 1880 Census I found - then I could use that to eliminate candidates from the New York City pool...