The legend that the wild horses on Assateague Island originated from a lost Spanish galleon has been handed down for centuries by the people of neighboring Chincoteague Island  whose ancestors owned land on Assateague centuries ago and raised horses there. It is not a modern invention to entertain tourists. When Marguerite Henry, the author of Misty of Chincoteague, came to Chincoteague in 1946 to see the horses and write about them, she met people who had received first hand knowledge of the legend from their ancestors. The National Park Service has put forth that the horses were put there and abandoned by the colonists in the seventeenth century.

Horses and cattle were raised there during this time but the Park Service historian did not examine the local records that showed that they were cared and accounted for. He also did not know that a huge storm occurred in October of 1749 that pushed a fifteen foot wall of water over the island drowning almost every horse and cow. In 1750, a Spanish ship wrecked and shortly thereafter, it was described that horses were running wild on Assateague and were smaller than the ones on the mainland. The Hidden Galleon describes in great detail the records on these horses and that horses were carried on other Spanish ships. It also recounts the author's meeting with Ronnie Beebe, the great nephew of Grandpa Beebe who told his grandchildren in Misty of Chincoteague, "legends are stories that be true!"