This is all information I got from a second cousin, David Hanson, when I was about 18 years old, and very unfamiliar with genealogy. David has since died.
Albert Gammell (b. 4 Nov 1840, d. 16 or 18 Dec 1863). Albert was married to Harriett Newell Randall (b. 21 May 1841, d 16 or 18 Dec 1863). Harriett was a sister of one of my ancestors.Albert and Harriett were married on 23 Jun 1861.They were killed by a train of the Eastern Railroad in Chelsea, MA, possibly when their carriage got stuck on the tracks.There is supposed to be an article about the accident in the Chelsea Telegraph and Pioneer (Sat 19 Dec 1863) but I haven't been able to investigate that yet.
Albert was in the 11th Mass Company I or D (conflicting information) starting rank 2nd Lieutenant, ending rank Captain. He was nominated for the Congressional Medal of Honor for the Chancellorsville Campaign. He may be mentioned in the book "Second Day at Gettysburg" by Harry Phanz (another source I haven't checked yet). He was the son of "late city missionary of that name in Charleston"... I apologize for the ambiguity here.
Albert's brother was Sereno D Gammell, who I found reference to on the Amherst College Class of 1865 site at www.amherst.edu/~rjyanco/genealogy/acbiorecord/1865.html. It mentions that he is the son of John and Susan W. (Mayhew), b. Charlestown, Mch. 2, 1842. There is more information on that particular site also.