The French colonial administration built Hoa Lo Prison in 1896. Originally intended to hold 450 prisoners, by the 1930s the number of detainees had soared to almost 2,000, the great majority political prisoners. Hoa Lo Prison achieved notoriety during the Second Indochina War as a place of incarceration for downed US pilots, who ironically nicknamed the prison the ˉHanoi Hiltonˇ. American prisoners of war held at Hoa Lo between 1964 and 1973 include Pete Peterson, who would later become the first US Ambassador to the Socialist Republic of Vietnam after the two countries established diplomatic relations in 1995; and John McCain, currently senior Republican Senator for Arizona and a recent presidential candidate, who was shot down over Hanoi in October, 1967.