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 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 the transition to the Alcatraz Federal Penitentiary. Though Alcatraz is now part of the Golden Gate National Recreation Area, the hospital is not included on the general tour. In 1870, the military hospital had ten beds, as well as tables, chairs, washstands, a dumbwaiter, and a closet. Measuring , it was heated by coal stoves. It was expanded in the late 19th century.