America is much larger, and much more inland than Western Europe, so horses are even more valuable in the American Middle Ages than the European Ages. Horses are expensive to keep, but they are worth their weight, and the value of horses has resulted in intensive breeding for the animal, especially in places like Kentucky and Texas. In fact, many are quite specialized for speed, luggage capacity, and of course, warfare.
As the herdsmen began to move eastwards, the rulers of the Eastern territories knew something had to be done. Because the herdsmen lived a more pastoral existence, they were better equipped to using horses and long range weaponry. The Warlords figured the best way they could handle this onslaught was focusing on defense. Therefore, America began to foster its first ever knights class.
Knights rely on strongly crafted and very heavy armor. several layers may be added on, depending on the battle or wealth of the knight. Most use leather, maybe even flexible woods from South America. the armor itself is formed into a coat-like structure, with impressive shoulder pads. At this point, the Knights will start adding the metal armor, usually a tunic made of scale male. The helmets are almost always metal, and they are curved to resemble the helmets of conquistadors. This is because, as most war is waged on the frontiers, fighting would like something like a brim to keep the sun out of their eyes. To do battle, knights carry massive wooden lances, used to hopefully penetrate the enemy, or at least incapacitate him enough to finish the job. Most nights carry, instead of longswords or broadswords, rather lithe fighting sabres.
Though most Knights exist in the Eastern forest zones, it's not unheard of out in the arid west. Nomads aren't as much of as threat out here, but it's still good to have forces to keep them at bay. Here, knights aren't part of a nobility caste. but servants of their Emperor. Because the Emperor can finance whatever war he wants, he can use valuable water to finance his armies. While the Non-Denom Church and the Warlords have a working, if not always smooth relationship, out in the west , Church and War are considered two very different things. But in the desert lands, Church and State are one, and as a result the Mormon army is also rather religious. This has rubbed off on the Buddhists.