Massachusetts Soldiers and Sailors, vol. XI (1902), p. 597: Oak, Calvin, Winchendon (Capt. Hale's and Capt. Wilder's companies, 1775) and the 1779 Leominster nine-months entry. Calvin Oak of Winchendon: private in Capt. Moses Hale's company on the Lexington alarm (6 days), then in Capt. Abel Wilder's company, Col. Ephraim Doolittle's regiment (muster roll 1 Aug 1775); and a separate entry for 9-months men engaged for Leominster in 1779.

Word-for-word transcription (spellings kept; uncertain letters in brackets).

OAK, CALVIN, Winchendon. Private, Capt. Moses Hale’s co. of militia, Col. Nathan Sparhawk’s regt., which marched on the alarm of April 19, 1775, to Cambridge; service, 6 days; reported enlisted into the army; also, list of men returned as serving on main guard under Maj. Loammi Baldwin at Cambridge, dated May 15, 1775; also, Capt. Abel Wilder’s co., Col. Ephraim Doolit’s regt.; receipt for advance pay, signed by said Oak and others, dated Charles- town, June 26, 1775; also, Private, same co. and regt.; muster roll dated Aug. 1, 1775; enlisted April 26, 1775; service, 3 mos. 13 days; also, company return dated Oct. 6, 1775.

OAK, CALVIN. List of 9 months men mustered by Thomas Newhall, Muster Master for Worcester Co.; Capt. Boutwell’s co., Col. Rand’s regt.; engaged for town of Leominster; mustered July 30, 1779; also, order on Henry Gardner, State Treasurer, dated Leominster, Aug. 18, 1780, signed by said Oak, for bounty due him for 9 mos. service in the year 1779.

Excerpt: the passage relevant to the family, not the whole page.