nne Marie Resseguie was seeking someone to treasure and restore her family home. Cass Gilbert, a very successful American architect, originally from the Midwest, made his family home in a townhouse on the East Side of Manhattan in New York City, and was looking for a summer home. In 1907 Mr. Gilbert and his wife, Julia Finch Gilbert, purchased the old tavern with its long roots extending back into early New England history. Anna Marie, who died in 1913 in the Bailey Inn once located across Main Street from her family home, left most of the furnishings in the house when she turned it over to the Gilberts.
Among Cass Gilbert's many architectural commissions were the Capitol of Minnesota, the Capitol of West Virginia, The U.S. Custom House and the Woolworth Building in New York City, the Library in Detroit, MI, many buildings at Oberlin College, and the Library on the Green in New Haven, CT. His last major commission was the U.S Supreme Court in Washington, D.C.
The Gilbert years at what the they called the "Cannonball House" changed the old farmhouse and inn into a wealthy family's summer home. Mr. Gilbert added bathrooms, a central heating system, and electricity. A large wing was erected over the 19th century basement of the back room to the rear of the building. The first floor of this wing contained a large dining room with north side French doors opening out onto a grape arbored patio and on the south a large bay window. Also included was a new pantry and kitchen. On the second floor of this addition were three bedrooms and two bathrooms and in the basement a laundry room with wash tubs. The arches in the graciously proportioned dining room came from the 18th century Bristol House that had been located on the Green in New Haven, Connecticut. When Cass Gilbert received the commission to design the library which is still there, he arranged to have the arches shipped to his home in Ridgefield and installed in his new dining room.
In 1907 Mr. Gilbert also designed and built the barn. The mid 19th century two story cottage was moved from its original site nearer the Tavern Building to its present location. A wing was added on the cottage's northeast corner that includes a bedroom and bathroom facilities. On Gilbert's plans this el is designated the chauffeur's room. The cottage was often used for guests in the Gilbert years. Today it is the home of the Museum's caretaker. In addition to household staff Mr. Gilbert had five gardeners employed on his estate.
Cass Gilbert designed and gave to the Town of Ridgefield the classic fountain that has graced the intersection of Main Street and West Lane since 1915.
Cass Gilbert died in 1934 while on a business trip to England. His widow, and other members of his family, continued to live in the "Cannonball House" until Mrs. Gilbert's death in 1956.