On this day in 1962, a high-flying U.S. U-2 spy plane took pictures over Cuba that showed Soviet missile sites. The State Department's Office of the Historian says the photos clearly showed sites for medium-range and intermediate-range nuclear missiles under construction. HISTORY.com says the missiles sat about 90 miles off the American coast.

Tension had been building since the failed Bay of Pigs invasion in April 1961. HISTORY.com says Fidel Castro was convinced the United States would try again and sought more military help from the Soviet Union, after which the number of Soviet advisers in Cuba rose to more than 20,000. The State Department says Soviet leader Nikita Khrushchev reached a secret deal with Castro in July 1962 to place nuclear missiles in Cuba to deter any future invasion.

President John F. Kennedy had warned the Soviets in public on September 4 against putting offensive weapons in Cuba, the State Department says. The photos showed that the warning had not worked.

The two sources differ on timing. HISTORY.com says the photos reached Kennedy two days after they were taken, while the State Department says they were presented to the White House the next day.

Kennedy then gathered his closest advisers. The State Department says some, including all the Joint Chiefs of Staff, wanted an air strike followed by an invasion, while others favored stern warnings. Kennedy chose a middle course and ordered a naval quarantine of Cuba on October 22.

The State Department says Soviet leader Khrushchev announced on October 28 that the missiles would be dismantled and removed from Cuba, and the U.S. ended its quarantine on November 20.

What we know: U-2 photos taken on October 14, 1962, showed Soviet missile sites in Cuba.
What we don't: The cited sources do not agree on exactly when the photos reached Kennedy.