"Complex warfare began with the rise of the Olmecs around 1150 B.C. on the Gulf Coast of Mexico and accompanied their cultural expansion, which was the first of three pre-Aztec expansions that gave Mesoamerica its cultural unity. The Olmecs expanded throughout much of Mesoamerica, apparently for trade purposes, although they were aided by the introduction of specialized military arms, including clubs, maces, and spears. By 550 B.C., however, the Olmecs withdrew into their homeland and Mesoamerica lapsed into a period of conflict between independent city-states."
* Sayer 1985 p25
"Men, when clothed, apparently wore loincloths, wide collars, pectorals, ear-plugs, armbands and tightly fitting helmets. Badly weathered relief carvings show towering head-dresses and hint tantalisingly at additional male garments such as short kilts, but it is hard to make out the details with clarity. It is widely believed that all later cultures in Middle America rest on an Olmec base, yet there is no way of evaluating their influence in costume and the textile arts."