Final answer:
Indian alliances were essential for European empires to establish power in the southeast, and land acquisition was the main motivating factor in early U.S. Indian policy, both statements being true. Additionally, the market revolution significantly transformed the U.S. socially and economically, which is also true.
Step-by-step explanation:
The statement that Indian alliances were pivotal for European empires to establish power in the southeast is true. These alliances were strategic for control and influence over the region, and commonly both parties sought to benefit from these collaborations. European powers like the French, British, and Spanish built relationships with various Native American tribes to gain advantages against their European rivals and to facilitate the exploitation of resources.
In terms of early U.S. Indian policy, it is true that the acquisition of land was a chief motivating factor. The government sought to expand territorially at the expense of Native American land, leading to policies that often resulted in forced removal and violent conflict, as seen in events like the Trail of Tears.
The market revolution did indeed bring substantial social and economic changes to the United States, including shifts in labor systems, the development of regional specialization, and significant improvements in transportation and communication networks. Thus, the statement is true.