For centuries, the Fort Massapeag land remained undeveloped under the ownership of the Jones family. This changed in the early 20th century when the land was sold for the large residential development known as Harbor Green to the Harmon National Real Estate Corp. in the 1930s.
During construction north of the Fort Massapeag site in the Harbor Green area, over 20 human skeletons were unearthed. The burial ground existed along Bay drive. This discovery and subsequent news coverage reignited the local legend of Captain John Underhill's alleged massacre. Treasure hunters were drawn to the burial site, and unfortunately, many artifacts were lost or destroyed due to lack of protection during construction. A significant amount of archaeological history in the northern Harbor Green area was lost.
Fortunately, the actual Fort Massapeag site itself was spared this fate and its historical significance was eventually recognized.