Barzillai Lew was known as "big and strong with an extraordinary talent as a musician." His 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 had two sons and two daughters. Primus served as a musician in the French and Indian War in 1747. Following his first wife's death, Primus married Rose Canterbury in 1752. They bought a farm on the west side of the Nashua River in the Pepperell section of Groton, Massachusetts and had two children together.
Primus and Margret Lew's oldest son Barzillai (pronounced BAR-zeal-ya) often called "Zeal" or "Zelah," was born 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. From March 10, 1760, to December 1, 1760, he served with the English forces against the French and Indians which marched northward for “the total reduction of Canada." He was probably present in the capture of Montreal by the British.