Before William Penn had his own colony, he was already drafting the governing charter for someone else's. John Fenwick, a Quaker who had purchased western New Jersey in 1674, founded Salem in 1675 as the colony's first English settlement, but a financial dispute between Fenwick and his partner Edward Byllynge left the colony's legal footing unsettled until Penn, acting as a trustee for Byllynge's creditors, drafted the Concessions and Agreements in 1677. That charter guaranteed freedom of conscience and personal liberty to every settler, established an annually elected representative assembly chosen by secret ballot, and required commissioners to negotiate directly and honestly with local Native chiefs before any land survey, protections stronger than almost anywhere else in English America at the time. Penn would not found Pennsylvania for another five years, and historians of the colonial period treat West Jersey's 1677 charter as a direct rehearsal for the religious liberty framework he later built at a much larger scale next door.
New Jersey's colonial religious geography ended up split along that same west versus east line, Quaker settlement in the west and a Dutch Reformed east settled out of New Amsterdam, before Newark and Jersey City later absorbed large Catholic and Jewish immigrant populations. The state today holds one of the country's most religiously diverse populations relative to its size, including significant Hindu, Sikh and Muslim communities, and Catholic identification leads at thirty three percent of adults, per Pew's 2023-24 study.