Barzillai Lew's story began with Primus Lew of Groton, Massachusetts (a former servant of Captain Matthew Bonner), and Margret Lew (a former servant of Samuel Scripture). As free blacks, Primus and Margret Lew married in 1742 and they had two sons and two daughters. Primus served as a musician in the French and Indian War in 1747. In 1752, Primus married again to Rose Canterbury and bought a farm on the west side of the Nashua River in the Pepperell section of Groton, Massachusetts and they had two children.
Primus and Margret Lew's oldest son Barzillai (pronounced BAR-zeal-ya) often called "Zeal" or "Zelah," was born a free black in Groton, Massachusetts November 5, 1743. Following in his father’s footsteps, Barzillai Lew was a fifer in Captain Thomas Farrington’s Company from Groton, which marched northward for “the total reduction of Canada." From March 10, 1760 to December 1, 1760, he served with the English forces against the French and Indians and was probably present in the capture of Montreal by the British. Lew was known as "big and strong with an extraordinary talent as a musician."