Carleton Watkins stereo views are among the first photographs of Yosemite. This view of Vernal Fall is one of approximately 100 stereo views and 30 mammoth-plate images made during his 1861 stay in the valley. His photographs helped raise public awareness of Yosemite's features and beauty.
"In December of  Watkin's Yosemite photographs were exhibited for the first time at the Goupil Gallery in New York City, and in 1863 Senator John Conness is believed to have shown them to President Abraham Lincoln, who responed by granting Yosemite Valley and the surrounding area to the State of California with the mandate that the site be forever in the public domain. Watkins's work thus played a part in the later estabishment of Yosemite National Park..." 1
1 Naef, Weston, Carleton Watkins in Yosemite (Los Angeles, CA: Getty Publications, 2008) p 5.