He is said to have been a participant in the First Battle of Saratoga (1777), at that part of the battlefield called Neilson Farm (Bemis Heights). Both before and after the battles, the heights were farmed by John Neilson, who joined the American troops opposing Burgoyne's advance. Today, Neilson's restored home looks much as it did when American staff officers used it for quarters in September 1777. The heights are named for Jotham Bemis, who kept a tavern at the foot of the hill. Posts now outline the fortified American line. The sites of General Gates' headquarters and the American field hospital are about 1/4 mile to the south.
The US Census of 1790, for Saratoga, shows: 1 male over 16 (Samuel III); 4 males under 16 (probably Amos, Peter, Elijah and Samuel IV) and 2 females (Rebecca and Jemima).
This date might be his baptism date, rather than his birthdate.