John Muir was important because he founded the Sierra Club and helped found national parks like Sequoia, Yosemite and the Grand Canyon.
Walden by Henry David Thoreau
The essay "Walden" by Thoreau was a narrative written about the author's stay through the winter and into spring in a hut on Walden Pond. The book describes the importance of self-reflection in the wilderness and the importance of nature in countering man's civilized life.
The Lincoln Administration passed the Homestead Act to get people to settle the Western part of the country for future use. Settlers were given hundreds of acres of land to use for agriculture and for homesteads.