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).
Though much of its early work was concentrated in California and the West, after mid-century the Sierra Club expanded its efforts nationally, opening an office in Washington, D.C., in 1963.