In early life he was a hatter by trade, later a shoe cutter. When the Great Rebellion broke out he enlisted in N.H. 1st Regt.; served three months; re-enlisted and served three years, and was discharged at the close of the war. He then engaged in the restaurant business and has now (1905) retired and resides in Haverill (Severance, B. Frank. Genealogy and biography of the descendants of Walter Stewart of Scotland and of John Stewart who came to America in 1718 and settled in Londonderry, N.H. Greenfield, Mass. : T. Morey & Son, 1905, pg. 163).
39th Mass. Infantry, Company L (Sons of Union Veterans of the Civil War, http://www.suvcwdb.org/home/index.php)
Severance states that his first wife Mary died (no date given) and Sylvanus then married secondly Bertha Eastman, on Oct. 8, 1885. But their shared grave marker lists the names of both Sylvanus and Mary and gives her death year as 1908, two years after Sylvanus died. Severance specifically states (page 163) that of the two children of Sylvanus, Ernest was the son of Mary and Efie the daughter of Bertha. I can find no reocrd of a marriage between Sylvanus and Bertha nor any record that shows them living together. The 1900 census shows Mary still with Sylvanus, and a Civil War widow's pension application dated 1906 lists Mary as his widow. However the 1900 census also finds a Bertha and Effie Stewart living as boarders in the West Newbury, Essex County residence of a Harry Shute. Bertha is also listed here as being divorced. Severance also has Effie born in 1886, but the 1900 census has her birth as November 1884, and her grave marker also has an 1884 birth year. Effie's middle name was "Washburn", which was Mary's maiden name. The mystery is solved by the book "Genealogy and biographical notes of John Parker of Lexington and his descendants" which is in Ancestry.com's "North American Family Histories" database - showing that Ernest, the son of Sylvanus and Mary, married Bertha, and that Ernest and Bertha are the parents of Effie.