The answer is: A system of classes that were organized like a pyramid
Slate is much more commonly found in wet areas, especially around rivers in the United States, so it wouldn't be very available to Natives who were more inland.
<span>The mongol Dynasty came last in the history of india. The Mongol Empire rose up out of the unification of traveling tribes in the Mongol country under the administration of Genghis Khan, who was announced leader of all Mongols in 1206. The domain became quickly under the control of him and his relatives, who sent intrusions toward each path.</span>
It was the "nativists" who believed that only long-ago immigrants from Western Europe could become real Americans, since they believed these immigrants were "natives" to the land.
