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 Hospital assigned to the Federal Prison Service. While a physician was in residence on the island through the 1950s, cost cutting measures included switching to private contracted physicians. Two of the most notable hospital patients were Robert Stroud, the "Birdman of Alcatraz", who had his own hospital cell; and Al Capone who spent more time in the hospital than in the general prison population. Alcatraz Hospital Alcatraz Hospital is a defunct hospital which was located on Alcatraz Island, California, US. It began operations in the 19th century while the United States Army operated Fort Alcatraz and continued to provide services after