Dahlgren Chapel is located at the summit of Turner's Gap in Western Maryland between Middletown and Boonsboro.
Most of the building materials came from the immediate area of the site, while a marble altar was imported from Italy.
When Mrs. Dahlgren died in 1898, she was interred in the chapel's family crypt.
After a period under the ownership of the Sisters of the Holy Cross from 1922 to 1925 the chapel returned to the Dahlgren family.
The property was acquired by the Central Maryland Heritage League in 1996.