TAH Summer Program Version of Primary Source Activity: Truman and the Atomic Bomb

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1. Overview

For over 60 years, historians have debated President Truman's decision to drop atomic bombs on the Japanese cities of Hiroshima and Nagasaki in August 1945. In this exercise teachers will examine a letter to Truman by Secretary of War Stimpson, diary entries written by Truman, an interview, and a White House press release that cast light on Truman's decision. Teachers will use these primary sources to address the following questions: Why did President Truman decide to use atomic bombs on Japan? How did Truman reach this decision?

2. Source Analysis

3. Group Discussion

Write three columns on the board: Notice, Questions and Historical Background. Use the following questions to guide the discussion:

  • What did you notice about each document? What surprised you? What questions do you want to ask about the documents, the context or the historical background?
  • What do you know about the Manhattan Project, the development of the atomic bomb, and the historical period that led up to the atomic strikes on Japan? How much did Truman know about the Manhattan Project before he became president? What was Truman's mindset about Japan and the Soviet Union during the Potsdam Conference and how did this affect his decision to approve use of the atomic bombs?

4. Historical Background

Present this historical background to enhance the group's knowledge of the time period.

  • Truman
    Truman took office as president upon the death of Franklin Delano Roosevelt (FDR) on April 12, 1945. At that time, Truman had no knowledge of the Manhattan Project and the development of the atomic bomb; he was never been briefed on the project by FDR. Truman was fully briefed on the Manhattan Project at the end of April 1945 by Secretary of War Henry Stimpson. In preparation for Truman's meeting with Churchill and Stalin at Potsdam, Truman appointed a high level group of officials called the Interim Committee to advise him on all issues related to the atomic bomb.
  • The Potsdam Conference
    In the early years of the war in the Pacific, FDR encouraged Stalin to declare war on Japan. He hoped that this would require Japanese troop commitment in Manchuria, leaving fewer Japanese troops to defend the home islands from an Allied invasion. By the spring of 1945, Soviet actions in Eastern Europe led the Truman administration to rethink its position about Soviet participation in the war against Japan. During the Potsdam Conference, Truman was informed of the successful test of the atomic bomb in New Mexico on July 16, 1945. Truman told Stalin, without elaboration, that the U.S. had a new significant weapon that he intended to use against Japan. Stalin told Truman at the conference that the Soviet Union would enter the war against Japan in August. The Potsdam Declaration issued by the allied powers on July 26, 1945, threatened Japan with "prompt and utter destruction" if it did not surrender unconditionally. The declaration did not address the status of the Japanese emperor in a post-war Japan, perhaps the most critical issue to the Japanese leadership.
  • The Atomic Bombs
    As Truman was en route home from Potsdam, he authorized the use of two atomic bombs on four potential Japanese targets - Hiroshima, Kokura, Nigata and Nagasaki - and transferred operational control over the weapons to the U.S. military. The targets were chosen, at the recommendation of the Interim Committee, because they were significant military targets surrounded by homes and other buildings that would be susceptible to damage so that the Japanese leadership could easily evaluate the devastating power of the atomic bomb.

    Hiroshima was bombed on August 6, 1945. Approximately 80,000 people were killed immediately with an additional 80,000 wounded. The Soviet Union declared war on Japan on August 8. On August 9, Nagasaki was bombed after the primary target - Kokura - was discarded for weather related reasons. At Nagasaki, approximately 40,000 people were killed with an additional 40,000 wounded. Japan surrendered on August 14, 1945, after the U.S. notified the Japanese leadership that the emperor would be permitted to continue to reign, albeit under the control of allied occupation forces.
  • U.S. Public Opinion
    Most Americans believed that Japan got what it deserved. The memory of Pearl Harbor had not faded. At the end of 1945, Fortune magazine published a survey showing that fewer than 20% of the American public had any moral reservations about the use of the atomic bombs, and more than 50% believed that the use of atomic weapons against Japan had been appropriate. An additional 23% of Americans indicated that they were sorry that the war ended before more atomic bombs could be used.

5. Conclusions

Who was the intended audience for each of the documents you analyzed? How did the intended audience shape the language and the message of that particular document? Are these messages consistent or do they indicate that the Truman administration had several competing ideas with respect to the bombs?

6. Classroom Applications

  • Do you think that this activity would work with your students?
  • How might you make changes to this activity to meet the needs of ESL and Special Education students?

Extended version

  • This primary source activity is also available in a extended version. Please click here to download the PDF-file