John Francis Mercer (May 17, 1759 – August 30, 1821) was a Founding Father of the United States, politician, lawyer, planter, and slave owner from Virginia and Maryland. An officer during the Revolutionary War, Mercer initially served in the Virginia House of Delegates and then the Maryland State Assembly. As a member of the assembly, he was appointed a delegate from Maryland to the Philadelphia Convention of 1787, where he was a framer of the U.S. Constitution though he left the convention before signing. Mercer was later elected to the U.S. House of Representatives from two different districts in Maryland. In 1801—1803, he served as Maryland's 10th governor.
Early life and education
Mercer was born in 1759 at Marlborough plantation in Stafford County in the Colony of Virginia, to prominent lawyer, planter and investor in western lands John Mercer and his second wife, the former Ann Roy (d. 1770), the daughter of Dr. Mungo Roy of Essex County, Virginia. His father John Mercer fathered 19 children by two wives, although many died before reaching adulthood. His father's first wife was Catherine Mason (1707-1750), daughter of burgess George Mason (1690-1735). His namesake half-brother, Captain John Fenton Mercer (1735-1756) had been killed and scalped in western Virginia during the French and Indian War. His elder half brothers George Mercer and James Mercer served in the Virginia House of Burgesses, and James also became a prominent lawyer and served in Virginia revolutionary conventions, the Virginia House of Delegates and the Continental Congress (1779-1780) before becoming a judge, ultimately of what later became the Virginia Supreme Court. Mercer also had several sisters and half-sisters who survived to adulthood, including Sarah Mercer who married Col. Samuel Selden of Stafford County, Mary Mercer who married Daniel McCarty Jr. of Westmoreland County, Anna Mercer who married Benjamin Harrison Jr., Grace Mercer who married Muscoe Garnett of Essex County, and Maria Mercer who married Richard Brooke of King and Queen County. His younger brother Robert Mercer (1764-1800) would marry Mildred Carter, daughter of prominent planter Landon Carter, and become a lawyer and editor of the "Genius of Liberty". Like all his brothers who lived to adulthood, Mercer attended the College of William and Mary, graduated in 1775 and read law with Thomas Jefferson.
Career
Soldier
During the American Revolutionary War, Mercer accepted a commission as lieutenant in the 3rd Virginia Regiment in the Continental Army. He was wounded at the Battle of Brandywine on September 11, 1777, and received a retroactive promotion to captain as of June 1777. On June 8, 1778 he became an aide-de-camp with the rank of major to General Charles Lee.
He resigned from the army when Lee did in July 1779, but by October recruited a cavalry company for the Virginia militia as the British navy discharged the British Legion and others to raid plantations in Chesapeake Bay. Thus Mercer held the rank of lieutenant colonel and served briefly under Lafayette as he led troops at the Battle of Guilford, Battle of Green Spring, siege of Yorktown and other locations.
Virginia politician
After General Cornwallis' surrender in 1781, Stafford County voters elected Mercer as one of their two representatives in the Virginia House of Delegates in 1782, where he served alongside Charles Carter. Fellow legislators selected Mercer as one of Virginia's delegates to the Continental Congress in both 1783 and 1784. When Richard Brent died, a special election to fill his place as Stafford County's delegate to the Virginia House of Delegates was held, and John Francis Mercer took his place for the rest of the session.
Maryland planter
In 1785 Mercer married his wife, as discussed below, and soon moved to Anne Arundel County, Maryland, where he operated her estates ("West River Farm") using enslaved labor. Sophia Mercer had received land and slaves under the terms of her grandparents' wills (5 slaves from her grandfather in 1782 and 19 slaves from her grandmother in 1789), Mercer brought 24 slaves from Virginia in 1798-1799, and another 11 slaves between 1799 and 1801 (including at least 3 inherited from his mother). In 1810 Mercer sold his slaves and plantation equipment in Anne Arundel County to his namesake son John, which together with digitizing issues makes the precise number of slaves he owned in 1810 and 1820 unclear. and 1820. Mercer owned 72 slaves by the time he died in 1821, which with his other personal property was valued at $19,976.75.