On October 1, 1890, Benjamin Harrison signed a bill setting aside roughly 1,500 square miles of the Sierra Nevada in California as Yosemite National Park. Yellowstone, created in 1872, had been the first. This one was different in one important respect: the valley floor and the Mariposa Grove had already been granted to the state of California in 1864, and the new park wrapped around them without taking them in. California kept the valley. It kept it until 1906.
The grant of 1864 was the first time any government had set land aside purely so that people could look at it, and it had not worked well. California appointed a commission, the commission had no money and no power to put anyone off the land, and by the 1880s the valley had hotels, private claims, fences and sheep. John Muir, who had come to the Sierra in 1868 and had spent years writing about the damage, decided the fix was to ring the valley with a federal reserve that had some force behind it.
He spent the summer of 1889 in the high country with Robert Underwood Johnson, the editor of Century Magazine, and the two of them ran the campaign in print. Congress passed the bill in September 1890. What the act protected was the watershed of the Tuolumne and the Merced, and that mattered as much as the scenery: San Francisco wanted the water and the Central Valley irrigation districts wanted it too. A park was a way to keep the headwaters out of private hands.
The act did not end the arguments. Sheep grazing went on in the high country for years, and the army ran the park, as it ran Yellowstone, until the National Park Service was created in 1916. The state handed the valley and the grove back to the federal government in 1906. Muir lost Hetch Hetchy. That valley was dammed in 1923.
The park covers about 1,200 square miles now and takes around four million visitors a year. The boundary drawn in 1890 is the reason the place survives in the shape it does, and that boundary was drawn in the first instance to keep sheep and water companies out.