This building technique is ancient and involves mixing damp earth with such stabilizers as sand, gravel and clay into a frame using pressure to create walls or blocks. Many such buildings around the world have survived for thousands of years.
The seven houses in Mount Olive are still standing. In 2009 an article at AL.com described the houses, their history, and included a photo of one of the houses. The article notes that each one-story house had about four acres and 1500 square feet of interior space.
The article identifies the architect on the project as Thomas Hibben. I have been able to find very little about him; one site devoted to rammed earth construction also identifies him as an engineer. Another site notes the project was so successful it attracted visitors from around the world, including Nehru from India.
Twenty-six photographs of the project taken by Hibben are available on the Yale University site devoted to photographers working for U.S. government agencies in the 1930's and 1940's. Ten of them can be seen below. One photograph of a rammed earth house on that site was taken by Arthur Rothstein during his April 1937 visit to Alabama. I have talked about other Rothstein photographs in three previous posts on this blog. The Hibben photographs are all labeled with just a year, 1937.