ORIGIN OF THE TERM "FAR-FETCHED"

It all comes from the age of exploration, after America was discovered. Sailors and explorers would bring back amazings creatures and products from their travels: Strange birds, tobacco from the Indies, spices that were never seen in Europe before, and so on. All these precious items were known as "far fetched goods", fetched from far away.
Often, with these imports came the stories surrounding them, tall tales about other people, strange creatures and places that the explorers had seen on their travels. These far fetched tales were heavily exagerated and tended to be treated with ecepticism, which is why the phrase has come to mean an improbable tale or story.