The Travis Mills Foundation announced the purchase Tuesday.
The foundation says it intends to make extensive renovations to the property and convert it into the nation's first fully accessible, "smart home" dedicated to serving the recreational and reintegration needs of combat-wounded veterans.
The estate was placed on the market last summer for $765,000, but the foundation did not announce the purchase price.
Arden built the main house in the town of Rome as her summer estate in the 1920s and later established the Maine Chance Spa at the site. Mamie Eisenhower, Judy Garland, and Ava Gardner were among the guests.
The property once covered 1,200 acres but was subdivided after Arden's 1966 death.