David C. Pierce is age 57 in the 1850 Federal Census at New Bedford, living with his second (or third?) wife Mary (Maria) age 52, Stephen age 29 (a ship carpenter), David B. age 20 (a house carpenter), and Lydia A. age 18. I don't know if Stephen was a son born to Hope before their marriage, or born to David and an earlier wife. That is certainly possible.
Four members of a Houghton family are also living in the household: John R. 25, Ann S. 33, Wm. H. 4, and Anna B. 2.
[S013771] Frederick Clifton Pierce, Pierce Genealogy No. IV, Being the record of the posterity of Capt. Michael, John and Capt. William Pierce, (Albany, NY: Joel Munsell's Sons, 1889), 287.
[S012563] Vital Records of New Bedford, MA to the Year 1850, Vol. II, 438.