Timothy Miller has written three books surveying American communes from 1900-2000. The books actually cover a greater arc since some communes that started before 1900 were still in existence in 1900, and many in existence in 2000 are still around today.
The books do not attempt to document all American communes. That would be almost impossible. There have been tens of thousands of communes throughout 300 years of American communal history. Some came and went without leaving much of a trace. The books give a sampling of history to illustrate the many flavors of communes, and to show how they influenced each other.
Miller lists seven conditions for a group of people living together to reach the level of being a commune. I have defined a new term: protocommune.
A protocommune is not quite a commune according to the seven conditions for a commune set by Miller. A protocommune has set the groundwork for, but has not quite reached the threshold of, being a commune according to Miller’s definition.
One other condition is required to be a protocommune: the people forming the commune should participate in regular meetings, or at least engage in regular communications, that have the intent of advancing the protocommune forward towards full commune status.