At the height of the "cold war," as critics of the Eisenhower administration complained about the growing "missile gap," the United States secretly gathered data on Soviet missile capabilities through photographs obtained from U-2 reconnaissance plane overflights of the Soviet Union. In May 1960, plans were finalized for a crucial Paris summit conference between western nations and leaders of the Soviet Union with disarmament to be the main focus. Hopes for a successful summit were dashed when on May 1, May Day, an American U-2 spy plane piloted by Francis Gary Powers was shot down over Soviet air space. On the first day of the Paris summit, Soviet Premier Nikita Khrushchev stormed out after delivering a condemnation of U.S. spy activities.

For documents on this topic, please see:

State Department statement on U-2 incident at May 5 Lincoln White press conference:
  U-2 Incident/Department Statement on U-2 5-5-60

State Department statement on U-2 incident at May 7 Lincoln White press conference:
  U-2 Incident/Department Statement on U-2 5-7-60

State Department press release #249 concerning U-2 incident:
  U-2 Incident/Dept of State Press Release 5-6-60

State Department press release #254 concerning U-2 incident:
  U-2 Incident/Dept of State for the Press May 9, 1960 No. 254 pg 1
U-2 Incident/Dept of State for the Press May 9, 1960 No. 254 pg 2

Memorandum of conversation, bipartisan leaders breakfast with the President, held in the State dining room, The White House concerning U-2 incident, intelligence and espionage:
  U-2 Incident/MemCon Pres Eisenhower at Bipartisan Leaders Breakfast 5-26-60 Page 1
  U-2 Incident/MemCon Pres Eisenhower at Bipartisan Leaders Breakfast 5-26-60 Page 2
  U-2 Incident/MemCon Pres Eisenhower at Bipartisan Leaders Breakfast 5-26-60 Page 3
  U-2 Incident/MemCon Pres Eisenhower at Bipartisan Leaders Breakfast 5-26-60 Page 4
  U-2 Incident/MemCon Pres Eisenhower at Bipartisan Leaders Breakfast 5-26-60 Page 5
  U-2 Incident/MemCon Pres Eisenhower at Bipartisan Leaders Breakfast 5-26-60 Page 6
  U-2 Incident/MemCon Pres Eisenhower at Bipartisan Leaders Breakfast 5-26-60 Page 7

Memorandum of Conference with the President; authorization by the President to produce 30 U-2 aircraft:
  U-2 Incident/MemConf, DDE on Nov. 24, 1954

Memorandum for record, authorizing one additional U-2 flight prior to May 1, 1960.  If this flight had been cancelled, the U-2 incident may have been avoided.
  U-2 Incident/Memo for Record by Andrew Goodpaster 4-25-60

Memorandum of conference with the President on October 26, 1959 concerning U-2 reconnaissance flights over Russia:
  U-2 Incident/Memo of Conference, DDE, Dulles, Goodpaster 10-30-59

Cover plan to be used for downed U-2 flight.  The U.S. did not know that the Soviets had the captured U.S. pilot:
  U-2 Incident/Memo re Cover Story 5-2-60

Memorandum for Director of Central Intelligence Agency concerning use of U-2 reconnaissance to determine status of Soviet ICBM program:
  U-2 Incident/Memo, for director of CIA re Talent 8-25-59 Page 1
  U-2 Incident/Memo, for director of CIA re Talent 8-25-59 Page 2
  U-2 Incident/Memo, for director of CIA re Talent 8-25-59 Page 3

National Aeronautics and Space Administration press release concerning missing U-2 airplane:
NASA Press Release May 5, 1960 Page 1

NASA Press Release May 5, 1960 page 2

Telegram from American Embassy in Moscow to Secretary of State transmitting translation of Soviet note concerning U-2 plane:
  U-2 Incident/Telegram, AmEmbassy Moscow to Sec of State No. 2780 5-10-60 Page 1
  U-2 Incident/Telegram, AmEmbassy Moscow to Sec of State No. 2780 5-10-60 Page 2
  U-2 Incident/Telegram, AmEmbassy Moscow to Sec of State No. 2780 5-10-60 Page 3
  U-2 Incident/Telegram, AmEmbassy Moscow to Sec of State No. 2780 5-10-60 Page 4
  U-2 Incident/Telegram, AmEmbassy Moscow to Sec of State No. 2780 5-10-60 Page 5
  U-2 Incident/Telegram, AmEmbassy Moscow to Sec of State No. 2780 5-10-60 Page 6
  U-2 Incident/Telegram, AmEmbassy Moscow to Sec of State No. 2780 5-10-60 Page 7
 

An exhibit of the U-2 plane wreckage and items retrieved from the plane and pilot was opened in Moscow to the people of the Soviet Union.  For photographs of this exhibit, please see:

Weapons, compass, etc. confiscated from U-2 pilot:
  U-2 Incident/79-5-14

Soviet Premier Nikita Khrushchev at exhibit in Moscow:
  U-2 Incident/79-5-11

Suicide needle to be used by U-2 pilots rather than risk capture in enemy territory:
U-2 Incident/79-5-12

Currency, watches and jewelry confiscated from U-2 pilot:
U-2 Incident/79-5-13

Radio-reconnaissance equipment and the antenna from the downed U-2 aircraft:
U-2 Incident/79-5-16

Parts of the fuselage and surveillance camera retrieved from the U-2 wreckage:
U-2 Incident/79-5-18

U-2 pilot's suit, helmet, etc.:
U-2 Incident/79-5-19

Soviet citizens viewing U-2 wreckage:
U-2 Incident/79-5-23

Central section of wrecked U-2 aircraft:
U-2 Incident/79-5-25

U-2 wreckage:
U-2 Incident/79-5-28

Flight path of the downed U-2 aircraft:
U-2 Incident/79-5-29

Photographs and information concerning Francis Gary Powers, the U-2 pilot:
U-2 Incident/79-5-8

Photograph of U-2 radio-reconnaissance antenna:
  U-2 Incident/79-5-17

For a listing of collections at the Eisenhower Library that contain materials on this topic, please see:
U-2 Incident/U-2 Paris Summit Search Report .

The following is a small list of secondary sources that are available on this topic:

The CIA and the U-2 Program, 1954-1974 by Gregory W. Pedlow and Donald E. Welzenbach, History Staff, Center for the Study of Intelligence, Central Intelligence Agency, 1998.

MAYDAY: Eisenhower, Khrushchev and the U-2 Affair by Michael R. Beschloss, Harper & Row, Publishers, New York, 1986.

Operation Overflight:  The U-2 Spy Pilot Tells His Story For The First Time by Francis Gary Powers with Curt Gentry, Holt, Rinehart and Winston, 1970.

Spy Flights of the Cold War by Paul Lashmar, Sutton Publishing,  1996.