On August 11, 1934, the first group of federal prisoners arrived at Alcatraz Island in San Francisco Bay. The former military prison had been converted into a high-security federal penitentiary. Authorities intended it for inmates considered especially dangerous or escape-prone. The isolated location, cold waters, and strong currents added a natural barrier to escape attempts. Over the years, Alcatraz housed notorious criminals such as Al Capone. The prison closed in 1963, but its history continues to capture public imagination.
