There are several interesting archeological, historical, and geographical correlations between the Olmecs and Jaredites.
A written secular history describing the origin of the Olmecs(which Joseph Smith never read), written about 1600 AD, tells of giant ancestors(Compare to Ether 15:26) who came from a great tower(Ether 1:33) where their language was not confounded(Ether 1:35). They traveled a long distance and had to cross many lands and waters(Ether 2:6) to reach their final destination. The Olmec civilization existed at about the same time period as the Jaredites. Both groups reached their height of civilization at about the same time and both were destroyed by civil war. Archeologists have discovered similar names engraved in ruins that match Jaredite names such as king Kish(Ether 10:17). (In Search of "Ancient Cumorah", a documentary by Stan Wadley)