When Prohibition officially ended on Dec. 5, 1933, police nationwide hoped underground crime would go with it. But after such a "singularly unedifying, shameful, thirteen-year-long hangover," as one historian put it, America had some serious cleaning up to do. The Bureau of Prisons looked no further than San Francisco Bay, to a Civil War-era Army prison on a small island called Alcatraz. First opened as a federal penitentiary in 1934, Alcatraz represented the end of the line for many ruthless criminals spawned by Prohibition. It was here that Chicago crime boss Al Capone served four years before dying of syphilis in a Baltimore hospital, and where the notorious bootlegger George "Machine Gun" Kelly spent the last 21 years of his life. Deemed both draconian and too expensive to maintain, the prison shut down in 1963 and now hosts thousands of tourists each year.