Despite the seeming unwisdom of doing so, James Mercer held on to
Marlborough until his death. He was an active patriot in the Revolution,
serving as a member of the Virginia Committee of Safety. Marlborough,
too, seems to have been a participant in the war, when Lord Dunmore, on
a last desperate foray, sailed his ships up the Potomac and attacked
several plantations. That Marlborough was a target we learn from the
widow of Major George Thornton of the Virginia militia, who "was at the
bombardment of Marlborough, the seat of Judge Mercer, on the
Potomac...."[143] In Purdie's _Virginia Gazette_ of August 2, 1776, we
read:
Lord Dunmore, with his motley band of pirates and renegradoes, have
burnt the elegant brick house of William Brent, esq., at the mouth
of Acquia Creek, in Stafford county, as also two other houses lower
down the Potowmack River, both the property of widow ladies.
Marlborough was no longer the property of a "widow lady," but accurate
reporting even today is not universal, and Marlborough may have been
meant. In any case, the mansion was not destroyed, although we do not
know whether any other buildings at Marlborough were damaged or not.
John Francis Mercer, James' half brother, appears to have lived at
Marlborough after his return from the Revolution. He served with
distinction, becoming aide-de-camp to the eccentric and difficult
General Charles Lee in 1778. When Lee was court-martialed after the
Battle of Monmouth, John Francis resigned, but reentered the war in
1780.[144] He apparently settled at Marlborough after the surrender at
Yorktown, at which he was present. In 1782 he was elected to both the
Virginia House of Delegates and the Continental Congress. General Lee
died the same year, stipulating in his will:
To my friend John [Francis] Mercer, Esq., of Marlborough, in
Virginia, I give and bequeath the choice of two brood mares, of all
my swords and pistols and ten guineas to buy a ring. I would give
him more, but, as he has a good estate and a better genius, he has
sufficient, if he knows how to make good use of them.[145]
It is not probable that John Francis' "genius" was sufficient to make
profitable use of Marlborough. He moved to Maryland in 1785, and later
became its Governor.[146]
James Mercer died on May 23, 1791. In 1799 the Potomac Neck properties
were advertised for sale or rent by John Francis Mercer in _The
Examiner_ for September 6. We learn from it that there were overseer's
houses, Negro quarters and cornhouses, and that "the fertility of the
soil is equal to any in the United States, besides which the fields all
lay convenient to banks (apparently inexhaustible) of the richest marle,
which by repeated experiments made there, is found to be superiour to
any other manure whatever." "30 or 40 Virginia born slaves, in families,
who are resident on the lands" were made "available."