City Readers Digital Historic Collections at the New York Society Library

John Stevens, Jr., the son of John Stevens, Sr. and his wife Ann Campbell, was born either in 1715 in Perth Amboy, New Jersey or on October 21, 1716 in New York City when his mother was visiting there.

With his brother Richard, he owned mercantile vessels and commanded them on voyages to Madeira and the Caribbean between 1739 and 1743. He then settled in Perth Amboy, where he was a vestryman at St. Peter's Church from 1749 to 1752. He was a large landowner in the New Jersey counties of Hunterdon, Union, and Somerset, and he owned a copper mine at Rocky Hill that was later abandoned.

Stevens was a member of the New Jersey General Assembly in 1751. He served as paymaster of the 1st New Jersey Regiment (the "Jersey Blues") under Colonel Peter Schuyler (New Jersey) from 1756 to 1760. In 1758 he was appointed by the Assembly of New Jersey to serve as a commissioner to the state's Indian tribes. In 1762 he was named a member of the New Jersey Provincial Council, a position that he resigned in 1770.

Stevens was a vocal opponent of the Stamp Act. When the act went into effect in 1765, he was one of a committee of four (with Robert Livingston, John Cruger, Jr., and Beverly Robinson) to prevent the issue of stamps in New York City. In 1770 he was appointed a commissioner, along with Walter Rutherfurd, to establish the partition line between New York and New Jersey.

In 1776, after the Provincial Congress had become the New Jersey Legislature under the state's first Constitution, Stevens was elected Vice-President of Council of New Jersey, holding the office of chairman of the joint meetings of the legislature until 1782. He represented Hunterdon County in the legislature during that period. He was president of the convention of New Jersey when the state ratified the United States Constitution on December 18, 1787.

He married Elizabeth Alexander, daughter of James Alexander, Surveyor General of New Jersey and New York and counsel for Peter Zenger, in 1748. They had two children:

• John Stevens III (1749–1838)
• Mary Stevens (died 1814), who married Robert R. Livingston, negotiator of the Louisiana Purchase.

His later years were spent with his son at Hoboken, where he died in May 1792. He was buried at the Frame Meeting House in Bethlehem Township, Hunterdon County, New Jersey.