1864 Yosemite Land Grant
President Abraham Lincoln signed the Yosemite Land Grant into law in 1864, giving the Yosemite Valley and the Mariposa Grove of giant sequoia trees to the state of California. (This happened eight years before the establishment of Yellowstone National Park, America's oldest national park.) Galen Clark was appointed Yosemite's first Guardian, a position held for most of the next 35 years.
But state protection of Yosemite Valley and the giant sequoia grove was not enough for conservationist John Muir. In 1868, Muir walked from San Francisco Bay to the Yosemite Valley. Inspired by the natural beauty he found there, Muir soon started writing about Yosemite in magazines and newspapers that reached audiences across the USA.
Muir also wanted to spread the word about the destruction of Yosemite's ecosystem that he was witnessing. Despite the park's protected status, he saw meadows being devastated by grazing livestock (which he called "hooved locusts"), especially in the high country. He also saw widespread deforestation caused by timber logging operations.
Muir's writing and his own personal passion for Yosemite and the Sierra Nevada helped spur a national conservation movement. Muir even escorted groups of influential people on guided trips into Yosemite and the surrounding Sierra Nevada to expound upon the importance of preserving nature. On one trip to Tuolumne Meadows, Muir together with Robert Underwood, editor the Century Magazine, came up with the idea to launch a campaign to make Yosemite a national park.
1890 Yosemite National Park
Their dream came true in 1890, when the land around Yosemite Valley and the Mariposa Grove of giant sequoias became part of Yosemite National Park. Congress also authorized the creation of Sequoia National Park and General Grant National Park (now part of Kings Canyon National Park) to preserve the giant sequoia forests found farther in the Sierra Nevada. The U.S Cavalry assumed jurisdiction of the new national park lands (learn more about the buffalo soldiers who served in the Sierra Nevada here).
But exploitation of the new national park's resources was still rampant, and the Yosemite Valley itself was still under state control. When Muir took President Theodore Roosevelt on a camping trip in Yosemite in 1903, he was able to convince the president of the importance of preserving more of the Sierra Nevada as federal land. Yosemite National Park as we know it today took shape in 1906, when Roosevelt took back control of Yosemite Valley from the state of California and protected the entire region as Yosemite National Park.
Muir continued to campaign for protection of wilderness in the Sierra Nevada for the rest of his life, although he lost the fight to save the Hetch Hetchy Valley, in the northwestern corner of Yosemite National Park, from being dammed (read more about the Hetch Hetchy controversy here).