Final answer:
Settlers moving west in the mid-nineteenth century called the land they were moving to the 'great American desert' initially, but as their understanding evolved, they saw it as a land of economic opportunities, driven by the ideology of Manifest Destiny.
Step-by-step explanation:
During the westward expansion of the mid-nineteenth century, settlers moving to the western territories of the United States referred to the land by different designations, predominantly influenced by their aspirations and the ideologies of the time. The notion of a “great American desert” was prevalent among early settlers, with this term underscoring the belief that the lands west of the Mississippi River were vast, arid, and inhospitable to civilization. However, as the 1840s approached and knowledge about the region grew, primarily through the promotion by land developers and the federal government, the perspective shifted dramatically. Settlers were motivated by the prospect of economic opportunities and the ideology of Manifest Destiny, which argued that it was their divine right to expand and settle the western territories spreading American values. Consequently, this land, once deemed unfit for habitation, came to symbolize progress, hope, and a new future for many settlers.