The first prefab?
From SciAm 1883, a neat idea that didn't seem to gain much traction until the 1920s.
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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.
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The floor plan of the assembled modules is also noticeably modern, more like a 1950s rancher than any 1883 house.