Alcatraz Island later invalidated the sale and paid Frémont nothing. Frémont 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 (1848) which ended the Mexican–American War, 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 San Francisco Bay. In 1853, under the direction of Zealous B. Tower, the United States Army Corps of
Legends of Alcatraz cells and locked cell doors shutting, to phantom figures in corridors, cold spots and even the sounds of musical instruments and sewing machines. Officials for Alcatraz have dismissed the reports of ghosts at Alcatraz as nonsense and deny their existence. Jerry Lewis Champion stated that it is "easy to see that Alcatraz Island contains all the legend and aura for the tales of ghosts and lost souls." The "Los Angeles Times" describes Alcatraz as the "most notorious federal penitentiary this country has ever known. Its history runs far and deep, as do the stories, the rumors, and the legends", and