The first prefab?
From SciAm 1883, a neat idea that didn't seem to gain much traction until the 1920s.
These modules were like pickup campers in modern terms. They were mounted on jacks, which could be raised to let a horsedrawn trailer slide under the module for transportation. The roof folded down on hinges.
The floor plan of the assembled modules is also noticeably modern, more like a 1950s rancher than any 1883 house.