June 1948-September 1949
Airlift in response to Soviet blockade of Allied controlled West Berlin

  1949
Soviets explode atomic bomb, closing gap with United States

  1951
US Air Force begins development of Atlas ICBM

  1952
United States explodes Hydrogen bomb

  1953
Soviets explode Hydrogen bomb

  1955
US Air Force contracts for Titan liquid-fueled ICBM

  October 4, 1957
Soviets launch Sputnik atop SS-6 missile

  1958
US Air Force authorizes production of solid-fueled Minuteman ICBM

  May 1, 1960
U2 spy plane downed over Soviet Union

  April 17, 1961
Unsuccessful invasion of Cuba at the Bay of Pigs by US backed exiles

  August 1961
Berlin Wall erected

  February 1, 1961
Succesful test launch of Minuteman at Cape Canaveral

  March 16, 1961
Construction of Minuteman site begins at Malmstrom AFB, Montana

  September 10, 1961
Groundbreaking for 44th Missile Wing at Ellsworth AFB, South Dakota

  October 1962
Cuban Missile Crisis: Kennedy demands Kruschev remove Soviet missiles from Cuba

First missiles in Minuteman Wing at Malmstrom AFB, Montana, activated on October 27; President Kennedy refers to them as his "Ace in the Hole"

Construction of 44th Missile Wing at Ellsworth AFB well under way

  November 1, 1963
44th Missile Wing at Ellsworth AFB declared combat ready; it will stay on alert for nearly three decades

  1967
1,000 Minuteman misiles deployed in hardened underground silos across the upper Midwest

  October 1971-March 1973
Ellsworth AFB refitted with Minuteman II misiles

  November 1989
Berlin Wall falls

  July 31, 1991
Bush and Gorbachev sign Strategic Arms Reduction Treaty; remaining 450 Minuteman II missiles withdrawn from alert

  December 3, 1991
First of Ellsworth's 150 missiles removed from its silo

  July 4, 1994
44th Missile Wing officially deactivated

  September 13, 1996
Last site destroyed, leaving only D-09 silo and D-01 launch facility to be preserved as Cold War historic sites