Sergeant was born in 1746 in Newark, New Jersey, to Abigail (Dickinson) and Jonathan Sergeant. He moved with his parents to Princeton. He completed his initial studies, attended the College of New Jersey (now Princeton University), and received his degree in 1762. His maternal grandfather, Jonathan Dickinson, was the first president of the college at its founding in 1747. He graduated from the College of Philadelphia (now the University of Pennsylvania) in 1763 with an A.B. degree. He studied law in the Princeton office of Richard Stockton,[1] was accepted into the New Jersey bar,[2] and entered practice in Princeton in 1767.[3]
From 1774 to 1776 he was a member of the revolutionary New Jersey Provincial Congress. He served as clerk to the Provincial convention in New Brunswick on July 21, 1774, and as a delegate and secretary to the convention held in Trenton on May 23, 1775. He was a member and treasurer to the New Jersey Committee of Safety.[2]
In early 1776, he was a delegate to the Continental Congress, but resigned in June to return home and serve on the committee that drafted the Constitution of New Jersey. On August 13, 1776, Sergeant wrote to John Adams of his plan to recruit a battalion of black slaves to help fight the British. Adams wrote back to Sergeant, "Your Negro battalion will never do. S. Carolina would run out of their wits at the least hint of such a measure."[5]
In November 1776, he returned again to the national congress.[3] In December 1776, Sergeant moved to Philadelphia after Hessian troops burned his house in Princeton.[1] In September 1777 he resigned from Congress a second time, this time to accept office as the attorney general of Pennsylvania.[3] He served as attorney general until his resignation on November 20, 1780.[6] He moved to Philadelphia and opened a law practice there in 1780.[3] He participated in the trial to settle the Pennamite–Yankee War land dispute between Pennsylvania and Connecticut.[1]
In 1775, he married Margaret Spencer and together they had eight children. Margaret died in 1787 and he re-married Elizabeth Rittenhouse, the daughter of David Rittenhouse, in 1778.[1]
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.[3]
