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Source set · 5 sources ✓ Lesson ready

Should the United States have dropped the atomic bomb?

Students examine the decision, the Potsdam ultimatum, and the human cost in Hiroshima.

Timeline of key events →

Teach it

✓ Lesson ready

A ready-to-run lesson for this set: Four Corners Debate. Slides include a hook, one slide per source, directions, a take-a-stand vote, an exit ticket, and a teacher script in the speaker notes.

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1. Hook: a striking quote 3-5 min

SIXTEEN HOURS AGO an American airplane dropped one bomb on Hiroshima, an important Japanese Army base.
President Harry S. Truman, statement of August 6, 1945 (Truman Library)

Ask: This is how Americans first learned about the atomic bomb. What does Truman emphasize? What does he leave out?

2. Main activity: Four Corners Debate

Grouping: Whole class, moving among four corners; small corner groups

Materials (printables are in the Lesson Plan Doc)
  • Four corner signs (printable pages in the Lesson Plan Doc)
  • Evidence cards for all 5 sources
  1. Preview evidence 5 min
    Pairs read the five evidence cards in date order (1941, 1943, July 1945, August 1945, the museum today).
  2. Move 3 min
    Read the four positions on the vote slide. Students walk to a corner.
  3. Build the case 8 min
    Corner groups choose their two strongest pieces of evidence and write a 45-second argument.
  4. Make the case 12 min
    Each corner presents. Students may switch corners after each speech. Count switches.
  5. Respond 8 min
    Each corner answers one question from another corner.
  6. Final position 5 min
    Students write their final position with one source.
  7. Exit ticket 5 min
    Students answer on a slip before leaving.

Take a stand: Should the United States have dropped the atomic bomb?

  • A. Yes: it ended the war quickly and avoided an invasion (Truman’s statement, Potsdam Declaration)
  • B. Yes, but only after a clearer warning or demonstration (Potsdam Declaration)
  • C. No: other options might have ended the war (Cairo and Potsdam terms, the timeline of surrender)
  • D. No: the human cost was too great (Hiroshima Peace Memorial Museum)

3. Pacing options

15-minute bell-ringer

  • 3 min Hook: Truman’s statement
  • 8 min Read the Potsdam warning and the Hiroshima museum description; students move to “yes” or “no” sides and defend
  • 4 min Exit ticket question 1

Full 50-minute lesson

  • 4 min Hook: Truman’s statement
  • 5 min Preview evidence
  • 3 min Move to corners
  • 8 min Build the case
  • 12 min Present and switch
  • 8 min Respond
  • 5 min Exit ticket
  • 5 min Buffer

4. Exit ticket

  1. Which source most influenced your corner? Explain.
  2. The Potsdam Declaration warned Japan of “prompt and utter destruction.” Was that a fair warning? Why or why not?

5. Differentiation

Support

  • Adapted Docs (easier reading) in this set: FDR Pearl Harbor Address
  • Give each corner its supporting sources listed on its sign.
  • Let students present in pairs.

Extension

  • Research the 1945 petition from Leo Szilard and other scientists (listed in the Truman Library collection). What did they ask Truman to do?
  • Compare how the Truman Library and the Hiroshima museum each describe August 6, 1945.

Suggested sequence

  1. Truman Library: Decision to Drop the Atomic Bomb
    Document collection · Truman Presidential Library · Great Depression & WWII (1929-1945) · Grades 9-12 · ⏱ 30+ min
    Documents on the decision to use the atomic bomb.
    Ask: Why did Truman decide to use the atomic bomb?
    Open with this source to frame the question.
    Original ↗Sourcing, Contextualization, CorroborationHIPP / HAPP
  2. Potsdam Declaration (Proclamation Defining Terms for Japanese Surrender)
    Document · Yale Avalon Project · Great Depression & WWII (1929-1945) · Grades 9-12 · ⏱ 10 min
    July 1945 Allied terms for Japan's surrender.
    Ask: Could the war have ended without the atomic bomb?
    Original ↗Copy DocSOAPSToneHIPP / HAPP
  3. Cairo Declaration (1943)
    Document · Yale Avalon Project · Great Depression & WWII (1929-1945) · Grades 9-12 · ⏱ 5 min
    The Allied statement on stripping Japan of its conquests and on Korea's future independence.
    Ask: How did WWII decisions shape postwar Asia?
    Original ↗Copy DocSOAPSToneHIPP / HAPP
  4. Hiroshima Peace Memorial Museum
    Image · Hiroshima Peace Memorial Museum · Great Depression & WWII (1929-1945) · Grades K-5, 6-8, 9-12 · ⏱ 15 min
    Museum collections and testimonies about the atomic bombing of Hiroshima.
    Ask: How should the bombing of Hiroshima be remembered?
    Original ↗See-Think-WonderOPTIC
  5. FDR Pearl Harbor Address
    Speech · National Archives · Great Depression & WWII (1929-1945) · Grades 6-8, 9-12 · ⏱ 10 min
    "Day of infamy" address, 1941.
    Ask: How did FDR rally the nation for war?
    Close with this source before writing.
    Original ↗Copy DocCopy AdaptedSOAPSToneHIPP / HAPP

Watch

Free videos to pair with this set. Preview before showing in class.

Teach with (more from Hillsdale): Unit 6: The Interwar Years and World War II (1919-1945) (free K-12 curriculum unit)

Culminating writing prompt

Using evidence from at least three sources in this set, write an argument that answers the question: “Should the United States have dropped the atomic bomb?” Cite each source by title, explain how its author, audience, and purpose affect its reliability, and respond to at least one counterargument.

Printable writing sheet (make a copy)

Students can plan with the Claim-Evidence-Reasoning organizer.