With Cuban leader Fidel Castro (right) fearing a U.S. attack after the disastrous Bay of Pigs invasion in 1961, Soviet leader Nikita Khrushchev (left) in 1962 ordered the construction of missile installations on Cuba and the deployment of nuclear weapons to the island.
A sign above the entrance to the U.S. naval base in Guantanamo Bay, Cuba in February 1962, six months before the crisis, reads: Republic of Cuba -- American free territory
U.S. aerial reconnaissance in October 1962 produced aerial views of medium-range missile bases on Cuba, confirming the most hawkish U.S. concerns.
U.S. President John F. Kennedy (right) meets for two hours with Soviet Foreign Minister Andrei Gromyko (center) and Soviet Ambassador Anatoly Dobrynin in Washington on October 18. The Soviets say aid to Havana is intended to boost the "defensive capabilities of Cuba."
President Kennedy says in a televised address to the nation on October 22 that "a series of offensive missile sites is now in preparation on [the] imprisoned island" of Cuba. He says their purpose "can be none other than to provide a nuclear-strike capability against the Western Hemisphere."
The UN Security Council meets in New York on October 23 to take up complaints by the United States, Cuba, and the Soviet Union.
With U.S. military forces at alert posture DEFCON 2 for the only time in U.S. history, President Kennedy signs an order on October 24 for a naval blockade of Cuba.
Mario Garcia-Inchaustegui, Cuba's ambassador to the UN, seen here (second from left) conferring with Soviet Ambassador Valerian Zorin (right), seeks a Security Council debate on the blockade, which he calls an "act of war unilaterally committed" by the U.S.
An "Moon" missile deployed during the Cuban missile crisis of 1962 on display at Morro Cabana complex in Havana in 2012.
U.S. Secretary of Defense Robert McNamara answers questions from reporters at the Pentagon on October 25, the day that President Kennedy sent a letter to Khrushchev laying the consequences of the crisis squarely on the Soviet leader's shoulders.
A Sopka missile deployed during the missile crisis of 1962 on display at the Morro Cabana complex in Havana in October 2012.
With the U.S. blockade in force, the "USS Joseph P. Kennedy" distroyer's crew boards and inspects the "Marucla," a dry-cargo ship under the Lebanese flag and under Soviet charter to Cuba, on October 26, 1962.
A U.S. administration official shows aerial views of one of the Cuban medium-range missile bases to the members of the UN Security Council on October 26.
Cuban antiaircraft gunners open fire on low-level reconnaissance planes over San Cristobal Site No. 1 on October 27, 1962. A U-2 reconnaissance plane is shot down, killing the pilot and producing the only casualty of the Cuban Missile Crisis.
Between October 25 and 27, Soviet leader Nikita Khrushchev and U.S. President John F. Kennedy (left to right, seen here at East-West talks one year earlier) agree that Soviet missiles will be removed from Cuba if the United States publicly pledges never to invade Cuba.
An aerial view shows three Soviet ships at Mariel naval port in Cuba waiting to be loaded with the missiles in accordance with the agreement on the withdrawal Soviet missiles.
The Soviet freighter "Anosov" carries missiles from Cuba.
With tensions lingering despite the U.S.-Soviet deal, Cuban leader Fidel Castro (center) inspects weapons at a military base on November 2.
The coffin of U-2 pilot Major Rudolf Anderson Jr., the crisis's lone casualty, is loaded onto a Swiss plane at Havana's airport on November 6, 1962 for repatriation to the United States.
U.S. forces also reinforced measures to protect the American naval base at Guantanamo Bay, Cuba. Here, soldiers check Cuban nationals leaving the facility in late November 1962.
A U.S. destroyer stops a Soviet cargo in order to check the freight on November 12, weeks after Krushchev announced the missile removals over Radio Moscow.
The Soviet freighter "Okhotsk" transports IL-28 missiles from Cuba on December 4, 1962.
A Soviet missile that was in Cuba and deactivated after the 1962 crisis but left on display there through 1991, when this photo was taken.