Working as an engineer in Indianapolis, a serious eye injury spurred him to travel to the Gulf of Mexico, which inspired his work A Thousand-Mile Walk to the Gulf.  
Ezra Carr, a former professor of his at the University of Wisconsin, introduced him to John Tyndall as well as to his future wife, Louisa Wanda Strentzel. He used his friendship with Edward Harriman in order to influence congress.  Working as an engineer in Indianapolis, a serious eye injury spurred him to travel to the Gulf of Mexico, which inspired his work A Thousand-Mile Walk to the Gulf.  His discovery of a glacier below Merced Peak helped him spread his theory of glacial erosion, but may be better known for opposing the Hetch Hetchy dam in Yosemite National Park.  FTP name this early American environmentalist and co-founder of the Sierra Club.
Ezra Carr, a former professor of his at the University of Wisconsin, introduced him to John Tyndall as well as to his future wife, Louisa Wanda Strentzel.
John {Muir}