 Sometime after 1855, Fatio added a second floor of bedrooms above the one-story wing on the north end of the main house.For years, experts thought the addition was completed during Margaret Cook's ownership in the 1830s.The theory was overturned in 2009, when dendrochronology experts from the University of Florida and the University of Tennessee dated the wood in the framing of the upper-floor wing to the latter half of the 1850s.