William Sanford Pennington was born in 1757 in Newark, Essex County, New Jersey, United States. He was the son of Mary (Sandford) and Samuel Pennington. William was the descendant of Ephraim Pennington who emigrated from England to New Haven, Connecticut, before 1643 and whose son, also named Ephraim, was one of the early settlers of Newark, New Jersey, where William Sandford Pennington was born three generations later.
Pennington's Revolutionary War diary, 1780 -1781, written while he was an officer of artillery stationed at and near West Point and now preserved in the library of the New Jersey Historical Society at Newark, shows a facility of language that bears witness to a good education. There is reason to believe that he learned the trade of a hatter. On the breaking out of Revolutionary hostilities he joined the Continental Army. He became a sergeant in the 2nd Regiment of Artillery on March 7, 1777, second lieutenant in 1780 to rank from September 12, 1778, and at the end of the war was mustered out as a captain by brevet.
William Sandford Pennington entered business at Newark, and he was elected to the state Assembly in 1797 and reelected in 1798 and 1799. He read law in the office of Elias Boudinot. In 1801, while still serving his clerkship, he was elected a member of the council, which, in addition to its legislative functions, acted with the governor as a final court of appeals and court of pardons.
In 1802 William Sandford Pennington was licensed as an attorney-at-law, in the same year was reelected to the council, and in 1803 was appointed county clerk of Essex County. In February 1804, before he had completed the three years of practice as an attorney necessary to qualify him for license as a counselor-at-law, he was elected by joint meeting of the Council and Assembly to fill a vacancy in the supreme court, the chief justice of which was Andrew Kirkpatrick. Notwithstanding Pennington's short experience as a practitioner, his mature age, natural abilities, and strong common sense supplemented by diligent study enabled him from the beginning to perform the duties of the office to the entire satisfaction of the bar and public.
In 1806 William Sandford Pennington published a Treatise on the Courts for the Trial of Small Causes, which he revised and published in a second edition in 1824. In 1806, under a new statute, he was appointed reporter to the supreme court and served as both justice and reporter until 1813. The two volumes of his reports contain the opinions of the supreme court, including his own, from 1806 to 1813 and are still essential to any New Jersey law library. In 1812 he was put forward by the Republican party for the office of governor but was defeated by a vote of twenty-two to thirty. In 1813 he defeated his former opponent by a vote of thirty to twenty, and he was reelected in 1814.
As governor, William Sandford Pennington was also chancellor and presided in the court of chancery. In 1815 he was appointed by President Madison as judge of the federal district court for New Jersey and held that office until his death. He died on September 17, 1826.
William Sandford Pennington was married twice: first, about 1786, to Phoebe, the daughter of James Wheeler, an officer of the Revolution, and second, after her death, to Elizabeth Pierson.
