The upstairs was not completed or furnished during Nathan's lifetime and was not even open to the public until eight years after the mansion first opened in 1948.
The second floor was intended to be the living quarters for Nathan and Jessie, as well as Jessie’s sister Mary when she traveled to Wisconsin.
Furniture in the guest room and the Belter room came from the Edward L. Paine Mansion. This Victorian mansion was built by Nathan’s grandfather and was Nathan and Jessie's Oshkosh home. No longer standing, the mansion was located where the Paine Prairie Woodland has since grown.