The document summarizes how the western frontier of the United States was acquired and settled between the early 1800s to late 1800s. It discusses how the US acquired land through treaties and wars with Mexico and Native Americans. It also explains some of the economic opportunities and challenges of settling the frontier, including ranching cattle, working on railroads, prospecting for gold, and living off the land through homesteading. Key events that enabled western expansion included the Louisiana Purchase, Mexican-American War, Gold Rushes, and the building of transcontinental railroads.

1. Western Frontier

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