On March 12, 1947, President Harry Truman went before a joint session of Congress and asked for $400 million in aid for Greece and Turkey. He argued that the United States should support free peoples resisting outside pressure. That pledge, the Truman Doctrine, came as postwar tensions were breaking up the wartime alliance with the Soviet Union, and it shaped American policy for decades.
This lesson covers Period 8 of AP US History, from 1945 to 1980. It is a crowded period, so this is an overview; later decks go deeper on the Cold War and the civil rights movement.
The big themes
- Global leadership. The US took on the role of leading a world order to contain Soviet power, with large consequences at home and abroad.
- Rights and the reach of government. Civil rights activists and liberal leaders expanded rights and federal programs, and those changes drew responses from both the left and the right.
- Prosperity and its divisions. Postwar growth built suburbs and optimism, while new social movements and Cold War worries divided Americans.
The Cold War
Diplomat George Kennan argued for containment. The Truman Doctrine, the Marshall Plan and NATO put it into practice in Europe, and NSC-68 called for a large military buildup. The Korean War ended in an armistice, with Korea still divided. The Cuban Missile Crisis in 1962 brought the two powers close to nuclear war. Historians still debate how much blame each side bears for the Cold War's origins.
The Red Scare
Fear of Soviet spying fed loyalty checks on federal workers and congressional hearings, including those of the House Un-American Activities Committee. Senator Joseph McCarthy made sweeping accusations from 1950 until the Senate censured him in 1954. The era raised a lasting question: how far can government go to protect security without harming civil liberties?
Prosperity and the suburbs
The GI Bill, a baby boom, highways and defense spending fueled growth. Millions moved to suburbs such as Levittown and to the Sun Belt. Not everyone shared equally: discrimination kept many Black families out of new suburbs, and critics such as Michael Harrington pointed to persistent poverty.
Civil rights
Brown v. Board of Education (1954) struck down school segregation, though many Southern districts resisted. The Montgomery bus boycott, the Little Rock Nine, sit-ins and marches built pressure for change. Congress passed the Civil Rights Act of 1964 and the Voting Rights Act of 1965. Other groups organized too: women through NOW, farmworkers under César Chávez and Dolores Huerta, and Native American, Latino and gay rights activists.
The Great Society and Vietnam
Lyndon Johnson's Great Society created Medicare and Medicaid and launched the War on Poverty. At the same time, the Gulf of Tonkin Resolution led to a major buildup in Vietnam. After the Tet Offensive in 1968, many Americans doubted government claims of progress, and antiwar protest grew. Johnson chose not to run again that year.
The 1970s: limits and a conservative revival
Richard Nixon pursued détente with China and the Soviet Union, and his administration created the Environmental Protection Agency. Watergate led to his resignation in 1974 and deepened distrust of government. Inflation, energy crises and debates over the Equal Rights Amendment marked the decade. A conservative movement, critical of federal power and social change, grew stronger.
Common mistakes students make
- Mixing up the Truman Doctrine and the Marshall Plan. The first was aid to Greece and Turkey against communist pressure; the second rebuilt Western European economies.
- Saying Brown ended segregation at once. It was a court ruling, and Southern resistance lasted years.
- Treating McCarthy as the whole Red Scare. Loyalty programs and HUAC hearings were already under way.
- Calling the 1960s only a liberal decade. Conservatives organized at the same time.
Frequently asked questions
What years does APUSH Period 8 cover?
Period 8 runs from 1945 to 1980. The Course and Exam Description weights it at 10–17% of the exam.
What are the main topics in APUSH Period 8?
The Cold War, the Red Scare, the postwar economy and culture, the civil rights movement, the Great Society, Vietnam, new social movements, and the environment.
What is containment in APUSH?
Containment was the US strategy of stopping the spread of Soviet power and communism, through aid, alliances and, at times, war.
Why did the Vietnam War divide Americans?
Rising casualties, the draft and doubts about government reports, especially after Tet, led many to question the war while others supported it as part of containment.
Try it
Say each answer before you flip the card. Then compare 1954 and 1965: a Supreme Court ruling came first, but the Civil Rights Act and the Voting Rights Act came only a decade later. What changed, and why then?
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