What metaphors are used in Brave Companions by David McCullough?

One of the metaphors behind many of the narratives is progress. Brave Companions deals with progress usually as a positive thing. Only Frederick Remington, the great illustrator and writer about the Old West has no use for change, the replacement of cattle roundups and cavalry encampments by sod huts and eventually towns. Aware the past he romanticizes is quickly passing, he writes and paints rapidly. In addition, Remington hates the masses of European immigrants ruining the nation and, consistently, refuses to own a car. His fellow traveler in preserving the Old West, Theodore Roosevelt, is not consistent, for he is the epitome of the Age of Progress and ultimate force behind the U.S. construction of the Panama Canal.