Final answer:
The spread of the pan-Indian movement in the Southeast was hindered by the population decrease due to diseases, forced relocation due to the Indian Removal Act, lack of recognition of tribal diversity by European settlers, and enforced ethnic regions isolating native groups.
Step-by-step explanation:
The spread of the pan-Indian movement in the Southeast was hindered by a multitude of factors. One significant obstacle was the devastation caused by diseases introduced by European colonists, which resulted in a drastic reduction of the Native American population, leaving only about 100,000 by 1830.
The established hierarchical societies with powerful chiefs often resisted unifying under a pan-Indian identity, favoring their tribal sovereignty and customs. Furthermore, the Indian Removal Act of 1830 forcibly relocated most of the native people from the Southeast to the plains, in a tragic event known as the Trail of Tears. This movement destroyed the existing social and political structures that could have supported a broader Indian alliance.
Additional impediments included the lack of recognition by European settlers and American officials of the diversity and individuality among tribes, as well as the deliberate generalization and simplification of native life, which served colonial and expansionist policies. The European desire to expand farms for cotton cultivation disregarded the Indians' rights to land, viewing their claims as an obstacle to national interests.
Lastly, the Enforced Ethnic Regions, like reservations, further isolated native groups from one another, hindering communication and unity to form a pan-Indian identity. The creation of Indian Territory and the relocation to unfamiliar environments under the Indian Removal Act also contributed to the disruption of alliances and the spread of unified movements among the tribes.