Why did Lewis Henry Morgan use Indigenous societies as examples in his evolutionary theory?

Lewis Henry Morgan utilized Indigenous societies as examples in his theory of cultural evolution because he viewed human history as a linear progression through distinct, universal stages: savagery, barbarism, and civilization.12

In his work Ancient Society, Morgan posited that all human groups pass through these same developmental phases, driven primarily by advancements in food production and technology. He categorized societies based on their level of social organization and material culture. By observing the Iroquois and other Indigenous groups, he sought to illustrate the earlier stages of this evolutionary sequence, which he believed preceded the "civilized" urban societies of his time.12

It is important to note that while Morgan’s focus on technological development is still recognized for its fundamental insights, his specific evolutionary framework—which ranked cultures on a hierarchical scale of progress—is now considered obsolete. Modern anthropology rejects the notion that societies are inherently "lesser" or "primitive" based on their social organization, affirming the ethical principle that all cultures possess equal human dignity and complexity.12