Nourse, Military Annals of Lancaster (1889), p. 34: the enlistment roll of 15 September 1755, in which the subscribers enlist in a regiment of foot raised to reinforce Major General Johnson's army, destined for Crown Point; the names include Seth Oak.
Image · dated 15 Sep 1755 · source: Henry S. Nourse, The Military Annals of Lancaster, Massachusetts (1889); Internet Archive (public domain).

How it is shown: Complete page as supplied; no crop, no retouch, no search highlight.
Keep in mind: What the page says: Confirmed from the page image. The roll is dated the fifteenth day of September 1755; the signers are listed in two columns and 'Seth Oak' is in the right-hand column between 'Fairbank Moor' and 'Benja Bridge'; Nourse adds that these soldiers from Lancaster and neighbouring towns served in Col. Josiah Brown's regiment and in the companies of Capt. Jeduthan Baldwin and Lt.-Col. John Cummings, with the muster rolls in the Massachusetts Archives. The page gives no town, age or parents for Seth Oak. Whether this is our person: Likely, not Confirmed, that this Seth Oak is the tree's Seth Oak (b. 1733), later Capt. Seth Oaks of the artificers (1777-78): the surname, the era and the Lancaster-Bolton area fit the Bolton marriage the tree records for him; the Westborough town record of 1733 names the parents (Nathaniel Oak and Tabitha) of a Seth Oake born there; that the 1755 enlistee is that Seth is Likely, and that his father is Nathaniel Oak Jr. rests on the 1906 register and the Rice wills (Likely). The roll does not name a colonel or company; Nourse says the soldiers on it served in Col. Josiah Brown's regiment and in other companies whose rolls are in the Massachusetts Archives, and prints the roll from the papers of Col. Oliver Wilder.