Alcatraz Island Juan Manuel Diaz, who charted San Francisco Bay and named one of the three islands he identified as "La Isla de los Alcatraces," which translates as "The Island of the Gannets" but is commonly believed to translate as "The Island of the Pelicans (Spanish for Pelicans is Pelicanos)," from the archaic Spanish "" ("pelican"). Over the years, the Spanish version "Alcatraz" became popular and is now widely used. In August 1827, French Captain Auguste Bernard Duhaut-Cilly wrote "... running past Alcatraze's (Pelicans) Island ... covered with a countless number of these birds. A gun fired over the feathered legions caused
Alcatraz Citadel compensation for his initiative in purchasing and securing Alcatraz Island for the U.S. government, but the U.S. government later invalidated the sale and paid Fremont nothing. Fremont and his heirs sued for compensation during protracted but unsuccessful legal battles that extended into the 1890s. Following the acquisition of California by the United States as a result of the Treaty of Guadalupe Hidalgo which ended the Mexican–American War (1848), and the onset of the California Gold Rush the following year, the U.S. Army began studying the suitability of Alcatraz Island for the positioning of coastal batteries to protect the approaches to