Exeter is one of the oldest remaining structures in southern Caroline County. Land records say that the Reverend Thomas Dill (Dell) received a survey certificate and patent for 50 acres on Marshy Hope Creek of the Northwest Fork of the Nanticoke River, then in Dorchester County and now in Caroline, and named the property Exeter after the cathedral in his county seat of Devon shire, England. The mill land changed hands many times, and in 1799 Abraham Lewis sold it to Solomon Bartlett, who is believed to have built Exeter, the miller's house across the road. Through later transactions the mill and house were purchased by John Elliott, who became known for modernizing the mill. Three generations of the Elliott family reportedly lived in Exeter as the last miller residents, and three generations of the White family were the last residents of the house. In 1967 Robert and Mary Holt bought the house and began restoring it to its original architectural character. A major renovation was completed in 2003 by Rudy Plutschak and his son Alan, and electricity was added for the first time, but only on the main floor; the house still has no indoor plumbing. The house, circa 1808, was listed on the National Register of Historic Places in 1978, and in December 2011 the Holt Family Trust deeded the property to the Federalsburg Historical Society. Idlewild Mill was one of the first grist mills near Federalsburg, standing on the Northwest Fork of the Nanticoke River where a large watershed and swift downgrade water power made it a favorable site. Courthouse records date the mill to 1734, though it may have operated earlier. Brothers Meshack Elliott and John Elliott bought the mill in 1825 and improved the grist mill, adding a carding machine for preparing wool for spinning wheels, a saw mill, and a smelting works. John Elliott also built the dam to increase the water power and a wooden bridge over the dam strong enough for wagon loads. In 1858 John Elliott's son sold the property to John W. Brown, who continued improvements. In the mid-1890s the property was sold to John F. Disharoon, and it was then last known as Idlewild Mills. It was remodeled again, and a power plant was built that supplied the first electricity to Federalsburg and several other towns. Fire destroyed the mill in 1915 and it was never rebuilt. The dam was destroyed in the great flood of 1935 and also was never replaced. The mill property is now part of the Idlewild Wildlife Management Area, owned and managed by the Maryland Department of Natural Resources.