Reader Morgan, from the Sustainable Life School, just uploaded this video of a very brief history of earthbag building.
I might add that missing from this history is the role that Gernot Minke at Kassel Polytechnic College in Germany played. In 1976 he began to investigate the question of how natural building materials like sand and gravel could be used for building houses without the necessity of using binders. The use of fabric-packed bulk material was found to be a cost-efficient approach. They used pumice to pack in the bags, because it weighs less and has better thermal insulating properties than ordinary sand and gravel. Their first successful experiments were with corbelled dome shapes (an inverted catenary) which was obtained with the aid of a rotating vertical template mounted at the center of the structure.
Nader Khalili is often credited with inventing earthbag building, but I would say that Gernot Minke deserves this distinction.