“The sod house or “soddy” was a successor to the log cabin during frontier settlement of Canada and the United States. The prairie lacked standard building materials such as wood or stone; however, sod from thickly-rooted prairie grass was abundant. Prairie grass had a much thicker, tougher root structure than modern landscaping grass.
Construction of a sod house involved cutting patches of sod in rectangles, often 2’×1’×6″ (600×300×150 mm) long, and piling them into walls. Builders employed a variety of roofing methods. Sod houses accommodate normal doors and windows. The resulting structure was a well-insulated but damp dwelling that was very inexpensive. Sod houses required frequent maintenance and were vulnerable to rain damage. Stucco or wood panels often protected the outer walls. Canvas or plaster often lined the interior walls.”
Image source: Sod House.org They say historians believe a million sod houses stood on the prairie.
Just for fun, do an Internet image search for “sod house inside” to see what these old houses looked like inside. (I grew up in Nebraska, so I have a natural interest in this sort of thing.)