One of the main arguments in favor of the idea that indigenous Americans were civilized is that they had complex social structures, with hierarchical governments, laws, and social norms. They also had advanced technologies, such as irrigation systems, metallurgy, and architecture. Additionally, they had a rich culture, with art, music, and literature.
However, some people argue that indigenous Americans were not civilized because they did not have a written language, and they did not build cities in the same way that other civilizations did. Additionally, they had different views on religion and morality than Europeans.
Ultimately, the question of whether or not indigenous Americans were civilized is a matter of opinion. There is no right or wrong answer.