What is the origin of the phrase "going south?"?

Question

For example, "if this project goes south, we'll pin the blame on Joe."

Answer 1

Mother Tongue Annoyances ( http://www.mtannoyances.com ) summarizes the origin of "go south" thus:

There seem to be two theories about the “south” in “gone south.” It may simply be a reference to the map-making convention that “south” on a map equals “down,” so to “go south” would be to head for the metaphorical bottom. A more intriguing theory is that the “south” originally referred to Mexico, to which one might well run in the early 20th century if one wanted, or needed, to elude legal pursuit and “disappear.”

The blog goes on to cite a corroborating explanation from the Online Etymological Dictionary ( http://www.etymonline.com/index.php?term... ):

go south: “vanish, abscond,” 1920s, American English, probably from mid-19th-century notion of disappearing south to Mexico or Texas to escape pursuit or responsibility, reinforced by Native American belief (attested in colonial writing mid-18th century) that the soul journeys south after death.

Answer 2

It originated during the American Civil War when army officers traveled with avions to the south.