DesBarres was a military officer, engineer, administrator and surveyor, and used his Falmouth estate as a base during his surveys for the Atlantic Neptune, a series of charts depicting coastal North America. He departed for England in 1773 to oversee the publication of the Atlantic Neptune but the estate continued to be administered as part of his holdings in Nova Scotia and New Brunswick. In 1784, he was appointed Lieutenant Governor of Cape Breton and later, Prince Edward Island. J.F.W. DesBarres retired at age 92 and died in Halifax in 1824 at the grand age of 103 (note- a more detailed account of DesBarres' life can be found in John Duncanson's book Falmouth-A New England Township in Nova Scotia 1760-1965).

Several archaeological features have been identified at Castle Frederick, varying in date from the early 1700s to the early 1900s. Prominent among these is the well-preserved foundation of the residence built by DesBarres in the mid-1760s and abandoned or destroyed some time early in the 1800s. A brick central chimney base and a stoned-lined well, were discovered during the 1990 field season. The sketch on the left is based on an 18th century watercolor of the DesBarres residence. Note the central chimney.

Many artifacts were recovered from the site of the DesBarres residence. The ceramic sherds below were found during test excavations in 1992. Both sherds can be placed within a date range from about 1760 to about 1830, which is consistent with the known history of the building. On the left is a rim sherd from a English white salt-glazed stoneware plate (bead and reel pattern) and on the right is a hand-painted pearlware saucer fragment, also made in England.