John Lamb was born in New York City on January 1, 1735, the son of Anthony Lamb. His father’s life had begun under difficult and notorious circumstances: Anthony, an Englishman trained in mathematical instrument making, became involved with the burglar Jack Sheppard and was transported to the American colonies in the 1720s. In New York he rebuilt his life through skilled work and commerce.

The younger Lamb trained as an optician and maker of scientific or mathematical instruments. This occupation demanded careful handwork, practical geometry, knowledge of lenses and metals, and the ability to serve navigators, surveyors, merchants, and other customers who relied upon precision instruments. It also placed him within New York’s community of artisans and shopkeepers rather than its landed aristocracy. Lamb later moved into the wine trade and became a prosperous merchant. Through importing and selling wine, he gained experience with shipping, customs regulations, credit, warehouses, and the commercial networks of the British Atlantic.

Lamb married Catherine Jandine and established a family in New York. His surviving reputation suggests that he was an effective writer and fluent public speaker. Those abilities, together with his ties to artisans and merchants, made him well suited to the popular politics that developed after the Seven Years’ War. New York’s waterfront economy was particularly sensitive to imperial trade policy and the presence of royal officials and troops.

The Stamp Act crisis of 1765 transformed Lamb from a tradesman and merchant into a public organizer. He emerged as a leader among the Liberty Boys and the Sons of Liberty, wrote political pieces and anonymous handbills, and helped mobilize opposition to parliamentary taxation. By then he was about thirty and already possessed the technical training, commercial independence, urban connections, and speaking ability that sustained his activism.