Final answer:
Settler colonies, like those in Australia by the British, were true forms of imperial expansion. The colonizationist scheme was not popular among black abolitionists, contrary to the suggested statement. Indian alliances were indeed important in assisting European empires to establish power in the southeast.
Step-by-step explanation:
When it comes to settler colonies established in empires, like Australia, yes, it is true that they were a form of imperial expansion during the colonial period. Settler colonies were territories governed by the immigrants from the colonizing country who settled in the colonies. For example, Australia was colonized by Britain and developed into a settler society where the British had a significant presence and displaced the indigenous populations.
Regarding the colonizationist scheme of the early 1800s, it was false to assume it was popular among black abolitionists. Many black abolitionists were opposed to colonization because it suggested that free African Americans could not be integrated into American society. An example of colonization was the establishment of Liberia in West Africa for freed slaves from the United States.
Moreover, it is true that Indian alliances were crucial for establishing power in the southeast for European empires. These alliances were a strategic part of colonial expansion, allowing Europeans to project power with fewer resources by leveraging local disputes and alliances.