My Great Great Grandfather in the 1860s lived down below the Blackwater Refuge outside Cambridge  in a single story 15'X16' home that was similar to the photo below. The 5 children slept in the rafters.  

Image below from Jack Barnes - Image Title: Eastern Shore home Uploaded: undefined
Image Info: This home, near Bishopshead, Md.[southwest of Cambridge down near the Bay], is typical of the homes of Waterman in the 1800s. George Barnes, my Great Great Grandfather raised 5 children in a similar home. They measured approximately 15' by 16' and the one shown is a single story. Bathrooms were outside and children slept in the attic.