Periodization Timeline

Jones AP US History 7 April 2013


Yalta Conference

February 1945

The Yalta Conference was the meeting of the heads of government of the United States, the United Kingdom, and the Soviet Union, represented by President Franklin D. Roosevelt, Prime Minister Winston Churchill, and General Secretary Joseph Stalin for the purpose of discussing Europe's post-war reorganization.

Atomic bomb drops on Hiroshima

August 6, 1945

America drops the atomic bomb on Hiroshima, Japan because the Japanese were not complying with American demands.

End of World War II

September 2, 1945

World War II ends after 6 years and 1 day. The end of World War II brought tension between the Allies, especially between Russia and the United States - they disagreed about how the European map should look and how borders would be drawn in the period following the war. Two superpowers were now against each other.

The Gouzenko Affair

September 5, 1945

Igor Gouzenko, a clerk working in the Soviet embassy in Canada defects and provides proof to the Royal Canadian Mounted Police of a Soviet spy ring operating in Canada and Ameirca, helping to change perceptions of the Soviet Union from an ally to a foe.

Long Telegram

February 22, 1946

George F. Kennan writes his Long Telegram, which describes his interpretations of the intentions of the Soviets.

Iron Curtain Speech

March 5, 1946

Winston Churchill makes his "Iron Curtain" speech, talking about the split of Europe between western, democratic nations and the Soviet communists.

Truman Doctrine

March 12, 1947

President Harry Truman announces the Truman Doctrine, giving aid to Greece and Turkey to prevent them from falling into Soviet hands and therefore, Communist.

"Cold War" term is coined

April 16, 1947

The term "Cold War" is coined to describe relations between the United States and the Soviet Union.

Marshall Plan

June 5, 1947

George Marshall makes a plan for a program of assistance to war-ravaged countries of Europe. Known as the Marshall Plan.

Marshall Plan signed into law

April 3, 1948

President Truman signs the Marshall Plan into effect.

Berlin Airlift

June 24, 1948

Stalin orders the blockade of all land routes from West Germany to Berlin, in an attempt to starve the French, British, and American forces from the city. In response, the three Western powers launch the Berlin Airlift to supply the citizens of Berlin by air.

NATO's formation

April 4, 1949

The North Atlantic Treaty Organization (NATO) is founded by Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom, and the United States, in order to resist Communist expansion.

Julius and Ethel Rosenberg

March 29, 1951

Julius and Ethel Rosenberg convicted of espionage for passing American secrets to the Soviets.

McCarthyism Starts

June 2, 1954

Senator Joseph McCarthy makes his first accusations of communism, that they have infiltrated the CIA and atomic weapons industry.

Soviets launch first man-made missile

October 1957

Soviets launch their first man-made missile. One of the many events in an expensive arms race between the U.S. and the Soviets during the crisis period of the Cold War.


October 4 1959

NASA is formed.

Bay of Pigs Invasion

April 1961

Invasion in Cuba which heightened the tensions during the Cold War.

Apollo Program

May 25 1961

President Kennedy announces the US intention to put the first man on the moon.

Berlin Wall

August 1961

East Germany builds the Berlin Wall.

Tsar Bomba

October 31 1961

The Soviet Union tests and then detonates the Tsar Bomba, the most powerful thermonuclear weapon ever tested, with an explosive yield of about 50 megatons.

Cuban Missile Crisis

October 16 1962

Soviets are secretly installing military bases with nuclear weapons on Cuba. President Kennedy orders a naval blockade of the island, intensifying the crisis and almost bringing the US and the Soviet Union to a nuclear war. They later reach a compromise.

Kennedy Assassination

November 22 1963

Kennedy is shot and killed by Lee Harvey Oswald. Some believe that communist countries were involved in his assassination, but nobody will ever know for sure.

Richard Nixon

January 20 1969

Richard Nixon becomes President of the United States.

U.S. lands first man on the moon

July 20 1969

The U.S. accomplishes Apollo 11, manned by Neil Armstrong, Buzz Aldrin, and Michael Collins.

Nuclear Non-Proliferation Treaty

March 5 1970

A treaty ratified by the U.K. with the Soviets and Americans.

Aid to Cambodia

November 18, 1970

United States begins aid to Cambodia to support the Lon Nol regime which is opposed by the Khmer Rouge and the Vietnamese Communists.

Four Power Agreement on Berlin

September 3 1971

Signed by the U.K., the U.S., the Soviet Union and France.


May 26 1972

Strategic Arms Limitation Talks (SALT I) starts. Signals the beginning of a détente between the U.S. and the USSR.

Apollo-Soyuz Test Project

July 1975

First joint flight of the U.S. and Soviet space programs - a symbol of détente and the true end to the space race.


June 18 1979

President Carter and Leonid Brezhnev sign SALT II, which outlined limitations and guidelines for nuclear weapons. Another sign of détente.

American Presidency

Franklin D. Roosevelt

March 4, 1933 - April 12 1945

Harry S. Truman

April 12 1945 - January 20 1953

Dwight D. Eisenhower

January 20 1953 - January 20 1961

John F. Kennedy

January 20 1961 - November 22 1963

Lyndon B. Johnson

November 22 1963 - January 20 1969

Richard Nixon

January 20 1969 - August 9 1974

Gerald Ford

August 9 1974 - January 20 1977

Jimmy Carter

January 20 1977 - January 20 1981


End of World War II (1945 - 1947)

1945 - 1947

The 1940s period during the Cold War was really only half of the decade, as the Cold War started when World War II ended in 1945. This period is characterized by the start of negative American sentiment towards the Soviet Union and the subsequent containment started with the Marshall Plan.

Beginnings of the Cold War (1947 - 1953)

1947 - 1953

Went from the advent of the Truman Doctrine in 1947 to the end of the Korean War in about 1953. The creation of the Eastern Bloc was in this time period as well. The Berlin Blockade was a part of this time period which served to heighten tensions, as well as the formation of NATO against the Warsaw Pact. This period is characterized with rising tensions which will develop and become the high point of the Cold War.

Crisis and Escalation (1953 - 1962)

1953 - October 16 1962

Starting with the death of Joseph Stalin and ending with the Cuban Missile Crisis, the Cold War found its peak in this time period. Unrest occurred in the Soviets' Eastern Bloc, and Eisenhower and Khrushchev's new take on leadership in the U.S. and the Soviet Union (respectively) shifted the dynamic of the Cold War. The Cuban Missile Crisis was the culmination of all the stress with the Cold War - the red scare and McCarthyism had tensions regarding Communist running high in America. The space race was started in this period as well.

Détente (1962 - 1979)

October 17 1962 - 1979

Americans, as participants of the Cold War, were forced to adjust to a new and more complicated pattern of international relations where the world was not divided into to clearly opposed blocs as it was before. The Cuban Missile Crisis in 1962 put fear in Americans of a nuclear war but by the end of the crisis, the Soviets withdrew their missiles from Cuba and so did America from Turkey. The U.S. won the race for space in 1969 when they landed the first man on the moon before the Soviets did, bringing much pride. Many symbols of détente were coming about in this period after the Cuban Missile Crisis.