History of the Yosemite area the Yosemite area in 1863. Pressure from Starr King and Olmsted, photographs by Carleton Watkins, and geological data from the 1863 Geological Survey of California prompted legislators to take action. Senator John Conness of California introduced a park bill in 1864 to the United States Senate to cede Yosemite Valley and the Mariposa Grove of Big Trees to California. The bill easily passed both houses of the United States Congress, and was signed by President Abraham Lincoln on June 30, 1864. The Yosemite Grant, as it was called, was given to California as a state park for "public use, resort
Yosemite National Park U.S. Congress authorized the O'Shaughnessy Dam through passage of the Raker Act. In the late 1920s a bid for Yosemite for the 1932 Winter Olympics was put forward. Ultimately, the 1932 Winter Olympics were awarded to Lake Placid, New York. In 1937, conservationist Rosalie Edge, head of the Emergency Conservation Committee (ECC), successfully lobbied Congress to purchase about 8,000 acres of old-growth sugar pines on the perimeter of Yosemite National Park that were to be logged. More recently, preservationists persuaded Congress to designate , or about 89% of the park, as the Yosemite Wilderness—a highly protected wilderness area. The Park