Lydia Hartwell after Joseph's death in 1849
Upon the death of her husband Joseph in the Gold Rush in 1849, Lydia Parker Hartwell became a 29-year old widow living in Salem, Massachusetts, with her four young sons: Joseph b. 1839, William b. 1845 (my great-great-grandfather), George b. 1847 and Daniel b. 1849.
Lydia Hartwell's residence in Salem
According to the 1857 Salem City Directory, Lydia Hartwell, widow, lived at 7 Park in Salem.
I was able to locate an 1856 map of Salem created by Henry Francis Walling, and have pinpointed the location of Lydia's house below. Note the proximity to Salem Harbor - I think it likely that Lydia and her young boys lived there while Joseph was away at sea.
On December 11, 1865, the widow Lydia Hartwell married the widower Joshua Nay in Salem, whose wife Sarah George had died the previous year.