This plan suggested a proposed expansion for the Executive Mansion attributed to First Lady Caroline Harrison around 1891. Compiled and drawn by architect Frederick Dale Owen, the plan proposes the addition of a private central court enclosed by historic and official wings as well as a series of greenhouses and conservatories housing palm gardens and a lily pond. While this proposal never came to be realized, the plan anticipates President Theodore Roosevelt's construction of the East and West Wings in 1902.

This pen and ink drawing by Fred D. Owen depicts plans to expand the White House made for First Lady Caroline Harrison. They include a new greenhouse on the South Grounds.