Just as much as the geography can define a world so can its history. Atlas is no different from Europe, Asia, or North America in this regard. The earliest history of Atlas is known to our world within some of our oldest legends and myths. The name of the continent is a clue to this history, Atlas because Island of Atlas which in Greek becomes Atlantis.

The original inhabitants of Atlas were humans, who were are a fairly advance stage of technological development... about 10,000 years before the start of the series. The human era ended when they tried to harness the power of magic and failed horribly. Their greatest cities were wiped out and what remained of the people left Atlas never to return. Most traces of their civilization were wiped out and the only clues of their existence lie either in the Great Wasteland in the center of Atlas or off the east coast where one of their cities sunk into the ocean.

After the Atlantians left Atlas the continent was plagued by disasters with the release of wild magics which in turn caused world to change and along with life as well. New races appeared on Atlas, first came the Dragons, then various chimera-esque races, the ponies were one of the last races to come into sapience.