William Bradford the younger was born September 14, 1755 in Philadelphia to Rachel Budd and William Bradford the Older, a printer who published The Weekly Advertiser, a newspaper which was distributed throughout the Philadelphia area. In 1762, he began to attend William Allen’s Academy of Philadelphia, which later became the University of Pennsylvania. Further research about the younger Bradford’s life during this period proves difficult since sources from the colonial period referred to both father and son with no differentiation.

After finishing his initial education at the Academy of Philadelphia in 1765, Bradford traveled to Princeton, New Jersey, to continue his studies under Reverend Richard Treat. In that same year, the British Crown passed the Stamp Act, which affected his father’s printing business. The Stamp Act required printers to put official seals on legal documents, newspapers, and other documents. The costly seal taxed the colonists to fund supplies and provisioning of British Regulars stationed in the American colonies after the Seven Years War. On October 31, 1765, the elder Bradford announced the Stamp Act’s enactment in his Pennsylvania Journal and Weekly Advertiser and said it constituted his want and need to find a way to "escape this insupportable Slavery." This sentiment illuminates the family’s growing discontent toward the Crown. Amid these educational and parental influences, the younger Bradford befriended several figures who later became notable during the Revolutionary War, including James Madison. Bradford studied history and moral philosophy, earning a second degree. He then returned to the Philadelphia area for legal studies under Edward Shippen, who later became a Chief Justice of Pennsylvania.

Bradford’s legal studies, however, were interrupted by the outbreak of the Revolutionary War. Coming from a place of discontent with how the British monarchy had been governing the colonies and (presumably) the effects this had on his father’s business, in 1776 Bradford joined the Continental Army as a private. He served with General George Washington at Valley Forge and rose to the rank of Colonel by April 1777. His service took him to battles at White Plains, Trenton, and Bound Brook. He retired from the services in April 1779 due to an unspecified illness.

After recovering, Bradford resumed his study of law in York, Pennsylvania. He became part of the Philadelphia Bar around 1774 and was admitted to practice before the Pennsylvania Supreme Court in 1779. The year 1791 would prove to be a pivotal one for Bradford. In August, Governor Thomas Mifflin appointed him as a justice of the Supreme Court of Pennsylvania and of the Pennsylvania Court of Appeals. In the same month, Bradford assisted in setting a major precedent for the United States Supreme Court in West v. Barnes, which concerned the validity of writs—commands or court orders—issued by various clerks and deciding which clerks were allowed to issue writs of errors, today known as "appeals." This also was the first ever Supreme Court case that included oral arguments, thus setting a precedent for oral argumentation for all future cases.

Adding to his legal claims to fame, Bradford was the second Attorney General of the United States, succeeding Edmund Randolph in January 1794. The governmental climate in the early 1790s in the newly-formed country was still tenuous. Parts of western Pennsylvania south of Pittsburgh were comprised of farmers who were vulnerable to Alexander Hamilton’s proposed Whiskey Excise Tax. Holding very little hard currency, they were accustomed to trading and bartering with whiskey. Discontent with the high taxes imposed by the new government, many of these farmers began to organize rebellious forces. Their protests included violent riots and physical harm to government officials. President George Washington sent Attorney General William Bradford, along with Senator James Ross and Pennsylvania Supreme Court Justice Jasper Yeates to settle what became known as the Whiskey Rebellion. Negotiations failed, however, and the federal commission headed by Bradford reported in September 1794 the need for military assistance to quell the uprising. When he later tried the rebels before the Supreme Court, Bradford argued that prosecution was justified on the grounds that the Whiskey Rebellion prevented the United State from executing its laws.

After the Whiskey Rebellion, Bradford pursued the case of Hylton v. United States, preparing it for the Supreme Court. While the case mainly concerned how taxes should be apportioned among the states, it also set a precedent for judicial review–the involvement of the Supreme Court in overturning laws that are unconstitutional–which was later formalized in a subsequent case, Marbury vs. Madison (1803).                

Unfortunately, Bradford did not live to see the court’s final decision on the Hylton case. He died on August 23,1795, at the age of forty. Nevertheless, he remains a prominent figure in the Revolutionary War era for his legal, moral, and governmental acumen that set precedents for Supreme Court argumentation and for recommendations on how the federal government should address armed rebellions. He was survived by Susan Vergereau Boudinot Bradford, the daughter of New Jersey Continental Congress delegate Elias Boudinot, whom he had married in 1785. William Bradford is buried in St. Mary’s Episcopal Churchyard in Burlington, New Jersey.