The Mara Salvatrucha gang originated in Los Angeles, set up in the 1980s by Salvadoran immigrants in the city's Pico-Union neighborhood who immigrated to the United States after the Central American civil wars of the 1980s.
Definition. The Sierra Club is the oldest grassroots environmental organization in the United States. The organization was founded in 1872 by a San Francisco group of professors, businessmen, and other professionals led by John Muir (Cohen 1985, 10).
Basically, the Sierra Club sees its purpose as preservation, protection, and enhancement of the natural environment (ibid). The organization continues to house its headquarters in San Francisco, with a legislative office in Washington, D.C, and chapters across the United States.