The Delger Mansion was the stately home of Frederick Delger and his family on 19th Street (then Frederick St.). It was built in 1873, 2 and demolished c.1923. 3
Lillian Moller Gilbreth was one of Delger's grandchildren, and probably spent time there as a child.
The house itself was large but not ornate, but the grounds included gardens, greenhouses, aviaries, and a teahouse. The OMCA Collections 1 contain many photos of the house and grounds, and even one of the servants. A sample of the photos is below.