Great Plains

The Great Plains are a broad, grassy, sloping expanse of prairie land that extends from Texas in the south to the Canadian provinces of Alberta, Saskatchewan, and Manitoba in the north. The climate is semi-arid and the dominant vegetation of the region is a large variety of tall and short grasses. Trees and woody plants tend to grow only along streams and rivers. The area was once home to millions of bison (and dozens of Native American tribes who followed and relied on the herds) that were systematically hunted to near extinction for their hides and tongues. The bison were gone, and the Native Americans were forcibly removed to reservations or driven away. The Homestead Act of 1862 promised 160 acres to anyone who could settle and live on their claim for five years. Settlers had to be 21 years old, the head of a family, or a citizen (or in the process of filing for citizenship). The arid region wasn't especially suited to farming and the going was rough for many homesteaders. Those immigrants who came from the grassy steppes of eastern Europe and western Russia fared better than others, but many faced such hardships that they gave up their claims and returned east.

From the game's History encyclopedia, AoE3: DE 100.19.18309.