who brought the term great plains into widespread usage?
The term "Great Plains", for the region west of about the 96th or 98th meridian and east of the Rocky Mountains, was not generally used before the early 20th century. Nevin Fenneman's 1916 study, Physiographic Subdivision of the United States, brought the term Great Plains into more widespread usage. Before that the region was almost invariably called the High Plains, in contrast to the lower Prairie Plains of the Midwestern states. Today the term "High Plains" is used for a subregion of the Great Plains.
Starting at the transition between the Middle to Upper Paleolithic period, some 80,000 to 70,000 years ago, some hunter-gatherers bands began to specialize, concentrating on hunting a smaller selection of (often larger) game and gathering a smaller selection of food. This specialization of work also involved creating specialized tools, like fishing nets and hooks and bone harpoons. The transition into the subsequent Neolithic period is chiefly defined by the unprecedented development of nascent agricultural practices. Agriculture originated and spread in several different areas including the Middle East, Asia, Mesoamerica, and the Andes beginning as early as 12,000 years ago.