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 Island August 1934. Alcatraz was designed to hold prisoners who continuously caused trouble at other federal prisons. At 9:40 am on August 11, 1934, the first batch of 137 prisoners arrived at Alcatraz, arriving by railroad from the United States Penitentiary in Leavenworth, Kansas at Santa Venetia, California, before being escorted to Alcatraz, handcuffed in high security coaches and guarded by some 60 special FBI agents, U.S. Marshals and railway security officials. Most of the prisoners were notorious bank robbers and murderers. The prison initially had a staff of 155, including the first warden James A. Johnston and associate warden J.