The plantation was bought by John Cooke of Stafford County. Cooke took
out an insurance policy on the mansion house on June 9, 1806, with the
Mutual Assurance Society of Virginia.[147] From this important document
(fig. 43) we learn that the house had a replacement value of $9000, and,
after deducting $3000, was "actually worth six thousand Dollars in ready
money." The policy shows a plan with a description: "Brick Dwelling
House one Story high covered with wood, 108 feet 8 Inches long by 28-1/2
feet wide, a Cellar under about half the House." Running the length of
the house was a "Portico 108 feet 8 Inches by 8 feet 4 Inches." A
"Porch 10 by 5 f." stood in front of the "portico," and another was
located at the northeast corner of the building, "8 by 6 feet." The
policy informs us that the house was occupied not by Cooke, but by John
W. Bronaugh, a tenant or overseer.
The records do not reveal how long the mansion survived. That by the
beginning of the century it had already lost the dignity with which
Mercer had endowed it and was heading toward decay is quite evident.
After John Cooke's death Marlborough was again put up for sale in 1819,
but this time nothing was said of any buildings, only that the land was
adapted to the growth of red clover, that the winter and spring
fisheries produced $2500 per annum, and that "Wild Fowl is in
abundance."[148]
Undoubtedly as the buildings disintegrated, their sites were leveled.
There remained only level acres of grass, clover, and grain where once a
poor village had been erected and where John Mercer's splendid estate
had risen with its Palladian mansion, its gardens, warehouses, and
tobacco fields. Even in the early 19th century the tobacco plantation,
especially in northern Virginia, had become largely a thing of the past.
Within the memory of men still alive, the one structure still standing
from Mercer's time was the windmill. Except for the present-day fringe
of modern houses, Marlborough must look today much as it did after its
abandonment and disintegration.