John Francis Mercer, born on May 17, 1759, was the fifth of nine children born to John and Ann Mercer of Stafford County, VA.
He attended the College of William and Mary, and in early 1776 he joined the 3d Virginia Regiment. Mercer became Gen.
Charles Lee’s aide-decamp in 1778, but after General Lee’s court-martial in October 1779, Mercer resigned his commission.
In 1782 Mercer was elected to the Virginia House of Delegates.
That December he became one of Virginia’s representatives to the Continental Congress.
He later returned to the House of Delegates in 1785 and 1786.
Mercer married Sophia Sprigg in 1785 and soon after moved to Anne Arundel County, MD.
He attended the Constitutional Convention as part of Maryland’s delegation when he was only 28 years old, the second youngest delegate in Philadelphia.
Mercer was strongly opposed to centralization, and both spoke and voted against the Constitution.
He and fellow Marylander Luther Martin left the proceedings before they ended.
In 1821 Mercer traveled to Philadelphia to seek medical attention, and he died there on August 30.
His remains lay temporarily in a vault in St. Peter’s Church in Philadelphia and were reinterred on his estate, “Cedar Park” in Maryland.
He allied himself with the Republicans and served in the Maryland House of Delegates in 1778-89, 1791-92, 1800-1801, and 1803-6.
Between 1791 and 1794 he also sat in the U.S. House of Representatives for Maryland and was chosen governor of the state for two terms, 1801-3.
During Thomas Jefferson’s term as President, Mercer broke with the Republicans and joined the Federalist camp.
His daughter, Margaret, born in Annapolis, Maryland, in 1792; died in Virginia in June, 1846, voluntarily reduced herself from affluence to poverty by freeing her slaves and sending them to Liberia, and she subsequently taught for twenty years in Virginia.
John Mercer’s third son was Judge James Mercer (1735-93).
Like his brothers he was an officer in the Virginia Regiment and at one point commanded at Fort Loudoun (modern Winchester, Virginia).
It appears to have been Judge James Mercer who succeeded to his father’s estate and who lived at Marlborough during the Revolution.
Judge James was a Virginia burgess and a great man in the Rappahannock Valley for many years. During the Revolutionary crisis, he was a key member of the Virginia Committee of Safety. He was a highly influential Freemason.
In fact, at 28 he was the second youngest of all the delegates.
He quickly established himself as a vocal foe of big government.
Like his kinsman George Mason of Gunston Hall, he believed that weaknesses in the proposed U.S. constitution did not adequately protect the rights of ordinary citizens from potential government tyranny.
He refused to sign it, and fought its adoption.
He published many of his Anti-Federalist views under the pseudonym, “A Maryland Farmer.”
In the fall of 1780, when the British invaded Virginia, he was commissioned lieutenant-colonel in General Robert Lawson’s corps, but the corps disbanded shortly.
He then commenced the practice of law in Fredericksburg, Va., and lived there until May of 1781, when he raised a troop of cavalry for further service.
At that time, he joined Lafayette, as colonel of his regiment participating with it until the termination of hostilities.