Grace hired New York City architect C. P. H. Gilbert to replace an older Italianate house that stood on the property with a new residence.

The house was designed in the French Renaissance style with a symmetrical façade and a U-shaped floor plan.

The projecting side pavilions flank a recessed central elevation with French doors on the ground floor topped with round arches.

[5] In December 2020, it was announced that attorney Ross Cellino purchased the Knox Mansion for $2,470,000 million from Computer Task Group in June 2020.

After they moved, the family continued to own 1035 Delaware which they rented out until 1922, when it was sold to the Roman Catholic Diocese of Buffalo for use as the official residence of the Bishop.