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
Alcatraz Federal Penitentiary legendary prison" suited to the times, which resulted in the Alcatraz Island Federal Penitentiary being nicknamed "Uncle Sam's Devil's Island." Despite Alcatraz being designed to house the "worst of the worst" of criminals who caused problems at other prisons, under the guidelines and regulations set by the strict prison administrators, courts could not direct a prisoner to be directly sent to Alcatraz, however notorious they were for misbehavior and attempted escape from other prisons. Prisoners entering Alcatraz would undergo vigorous research and assessments prior to their arrival. Security in the prison was very tight, with the constant checking of bars,