Hennessy Hall – Fairleigh Dickinson University

Date of Construction: 1887
Historic Architect: McKim, Mead, and White
Landscape Architect: Frederick Law Olmstead Sr.& Alfred Parsons
Historic Designation: Eligible for Individually Listing on the National Register of Historic Places
Size: 55,000 S.F.
Client:  Fairleigh Dickinson University


Hamilton McKown Twombly and Florence Adele Vanderbilt Twombly purchased 1200 acres in Madison, NJ, which they developed into Florham, their summer estate. The monumental English Georgian style mansion has over 100 rooms and one of the largest homes ever constructed in the United States with terraced gardens, including a sweeping approach to the mansion. In 1908 English Landscape architect Alfred Parsons reworked the grounds around the mansion. His renovation included expanding the upper fountain, remodeling the existing garden retaining wall and adding the massive concrete perimeter wall, the lower fountain, the elliptical balustrades at the main approach to the mansion, and extending the terrace to the south of the mansion into the formal Italian garden featuring a pergola and parterre. In 1958, Fairleigh Dickinson University purchased the last 178 acres of the estate including the mansion which is now called Hennessy Hall and serves as the administrative and academic center for the University’s Madison Campus.

Condition Assessment Master Plan

  • sUAS Condition Survey
  • Non-Destructive Evaluation Assessment
  • Structural Condition Assessment and Probe Investigation
  • Material Testing and Analysis
  • Emergency Stabilization
  • Phased Recommendations
  • Cost Estimating