He was born in 1746 in Newark, New Jersey, United States, the eldest son of Jonathan and Abigail (Dickinson) Sergeant, and a descendant of Jonathan Sergeant who came to New Haven, Connecticut, in 1644, and soon moved to Branford. His father was a brother of John Sergeant, missionary to the Indians; his maternal grandfather was the Rev. Jonathan Dickinson, first president of the College of New Jersey. His father was treasurer of that institution from 1750 to 1777.
Sergeant was graduated there in 1762, and the following year from the University of Pennsylvania.
Like most other young Princetonians, he fell in with the Sons of Liberty and took a prominent part in the Stamp Act controversy. Six short years, 1774 to 1780, cover the entire official life of Sergeant, yet they were momentous enough to prove that John Adams was correct in speaking of the sociable young lawyer in 1774 as a "cordial friend to American liberty".
He was clerk of the first Provincial Congress of New Jersey in July 1774; served on the Somerset and Princeton committees of correspondence in 1774 and 1775; was secretary of the second Provincial Congress, and at the meeting in August 1775 was made provincial treasurer, receiving in October the thanks of that body for his services.
In February 1776 he was chosen to represent New Jersey in the Continental Congress, but in June he resigned to accept a seat in the New Jersey Provincial Congress. Here he learned his first lessons in the art of protecting liberty with laws, directed against the Loyalists, such as he later became expert in enforcing. On November 30, 1776, he was again chosen member of the Continental Congress, serving until September 1777. When Hessians burned his Princeton home on December 25, 1776, he definitely moved his residence to Philadelphia, identifying himself with Pennsylvania politics.
He was appointed attorney general of Pennsylvania on July 28, 1777, but not commissioned until November 1, and apparently he engaged in private practice in the interim. His extraordinary procedure in the typical trial of Samuel Rowland Fisher, a Quaker and suspected Loyalist, shows that Sergeant, like most Revolutionary public prosecutors, took rather literally the ancient maxim inter arma leges silent. Arduous labor and small pay did not deter him from conducting a "great number of capital trials" before his resignation, November 20, 1780.
He declined public office after the Revolution, devoting his attention to law. His defense in 1788 of the Anti-Federalist editor, Eleazar Oswald, indicates that he was still in alignment with the Bryan faction.
Sergeant died in Philadelphia in 1793.
Serving in New Jersey Provincial Congress, Jonathan Sergeant took the lead in forming a state constitution. As one of the McKean-Bryan "Constitutionalists, " he was made a member of the council of safety. As an attorney General for the state of Pennsylvania he assisted the state in several notable trials, chief of which was the Connecticut-Pennsylvania dispute arbitrated at Trenton in November and December 1782.
Zeal for Republican principles led him to espouse the French Revolution, and during the excitement of the Genet episode, he took a leading part.
Quotes from others about the person
Thomas Wharton thought him a "worthy young man. "
In June 1787, his twenty-eight-year-old wife, Margaret Spencer, whom he had married March 14, 1775, died, leaving him eight children, two of whom were John and Thomas, and on December 20, 1788, he married Elizabeth, daughter of David Rittenhouse, by whom he had two daughters and a son.
His son John Sergeant later represented Pennsylvania in the U. S. Congress. Another son, Thomas Sergeant, served as Pennsylvania secretary of state, attorney general and on the state Supreme Court.
