In the early 1800’s Thomas and his wife Lucy bought land on Cumberland for a winter retreat. In 1884, they began building a mansion on the site of Dungeness. Thomas resolved to retire from business and spend more time in Georgia. The stress of working for his brother had left him exhausted. Sadly Thomas never lived to see its completion. Lucy and their nine children continued to live on the island, naming their mansion Dungeness after the original building built by Nathaniel Greene. Dungeness was designed as a 59-room Scottish castle. They also built pools, a golf course, and 40 smaller buildings to house the 200 servants who worked at the mansion. The last time Dungeness was used was for the 1929 wedding of a Carnegie daughter. After the Crash and the Great Depression, a lot of the family left the island and kept the mansion vacant. It burned in a 1959 fire, believed to have been started by a poacher who had been shot in the leg by a caretaker weeks before. Today, the ruins of the mansion remain on the southern end of the island. The family owned 90% of the island. Lucy Carnegie had additional estates built on the island for her children. These include:
Greyfield, built in 1900, now a private inn.
Plum Orchard, donated to the National Park Service in 1972, which maintains it.
Stafford Plantation, still family owned.
In 1954 in an effort to save the Cumberland Island from development, members of the Carnegie family invited the National Park Service to the island to assess its suitability as a National Seashore. In 1955 the National Park Service named Cumberland Island as one of the most significant natural areas in the United States and plans got underway to secure it.
The bill was signed by President Richard Nixon on October 23, 1972 and Cumberland Island became a national park for everyone to enjoy.