"The characteristics of these new missile sites indicate two distinct types of installations. Several of them include medium range ballistic missiles, capable of carrying a nuclear warhead for a distance of more than one thousand nautical miles. Each of these missiles, in short, is capable of striking Washington, DC, the Panama Canal, Cape Canaveral, Mexico City, or any other city in the southeastern part of the United States, in Central America, or in the Caribbean area."

Kennedy had a warning for the Soviets.

JOHN KENNEDY: "It shall be the policy of this nation to regard any nuclear missile launched from Cuba against any nation in the Western Hemisphere as an attack by the Soviet Union on the United States, requiring a full retaliatory response upon the Soviet Union."

Kennedy and his national security advisers debated what to do about the Soviet missiles in Cuba. Should the United States launch an air strike and try to destroy them? What if some of the nuclear missiles escaped the attack?

Kennedy decided to use a naval blockade -- he called it a "quarantine" -- to prevent any more Soviet ships from reaching Cuba.

This photograph, made Oct. 23, 1962, shows a ballistic missile site project in the San Cristobal area of Cuba. The photo was released by the Defense Department.

There were tense negotiations with the Soviets. Khrushchev demanded a promise that the United States would not invade Cuba. Kennedy agreed, and did so publicly. Secretly he also agreed to another demand. He promised that the United States would remove its Jupiter missiles based in Turkey, after the crisis was over.