Final answer:
Ethnocentrism, paternalism, racism, and imperialistic ambitions drove Euro-American attitudes that led to the subjugation and displacement of indigenous populations, sparking resentment and the formation of pan-Indian alliances in response.
Step-by-step explanation:
The attitudes of Euro-Americans that inspired hostility and calls for pan-Indian alliances primarily stemmed from ethnocentrism, paternalism, racism, and imperialistic policies. The Euro-American perspective often cast indigenous peoples as either in need of assimilation to European norms or as natural losers in a 'Darwinian contest' between civilization and savagery. This contributed to policies and actions that sought to subjugate and displace Native Americans, which in turn prompted various indigenous groups to form pan-Indian alliances as a means of resistance.
During the Indian Wars and beyond, opinions in the eastern United States were divided but many still viewed Native Americans through a lens of deep-seated prejudice, as shown by the infamous phrase by General Philip Sheridan, "the only good Indian was a dead Indian." Combined with land speculators' desires and reformers' inconsistent advocacy for assimilation rather than cultural respect, there was widespread support for policies that harmed Native American societies.These attitudes and the desire for land and power resulted in a legacy of resentment and hostility that drove Native Americans to seek unification in various forms of pan-Indian movements, fighting against the exploitation and destruction of their cultures and lands.