Ancient civilizations, such as the Atlantean, Lemurian, La, Ur, and Da civilizations, are believed to have contributed to the development of later civilizations. Edgar Cayce, a psychic medium, believed that these civilizations were influenced by the Incal, Oz, and Mu civilizations. Cayce also believed that the Mayan civilization was a mixture of different civilizations, including the Lost Tribes, Mu, and the Aztec. The Mayan civilization was influenced by Iltar and his followers, who left Atlantis and settled in Yucatan.

Cayce believed that the Mayan civilization was destroyed by physical changes in the land, which were caused by the final upheaval of Atlantis.

In his psychic readings he referred to several ancient civilizations, highlighting their geographical and historical significance:

• Sahara and Nile Region: Initially, this area was mentioned as one of the primary locations where humans dwelled. It was described as a place where the waters entered the now Atlantic, rather than flowing northward, indicating a very ancient time before known historical records.

• Tibet, Mongolia, Caucasia, and Norway: These regions were also mentioned as initial places of human habitation. The waters from Tibet and Caucasia were said to enter the North Sea, and those from Mongolia entered the South Seas.

• Southern Cordilleras and Peru: In the southwestern hemisphere, these areas were noted as initial human settlements with waters entering the Pacific.
• Utah, Arizona, Mexico: In the northwestern hemisphere, these areas were described as places where early humans settled, with waters entering the Northern Seas.
• Egypt: Specifically, the readings focus on a period during the rule of the second ruler in Egypt, who was significant for giving the first laws concerning man's relation to the Higher Forces. This ruler gathered wise men to compile teachings for the indwelling of the Divine Forces, marking a significant development in human civilization's relationship with spiritual laws.

These references sketch a broad and mystical view of human civilization's spread and development across different regions of the world, as per Cayce's psychic readings.