Yea so um social studies is hard and i don’t understand this

This excerpt supports the idea that the sky chief valued

Why does c. wright mills identify critical thinking as one of the most important criteria for the development of intellectual craftsmanship? why is constantly being aware of the biased nature of your reactions and interactions (what c. wright mills calls self-reflexive) key to the development of that critical thinking? finally, why is keeping a file important, how can it lean to intellectual curiosity which can foster critical thinking and to develop a keen analytical mind?

Which of the following items would serve as a primary source for a historian studiying the american civil war