Dakota Datebook

Leon Jacobson and the Atomic Bomb

Friday, December 2, 2011


On this date in 1942, in an inconspicuous laboratory at the University of Chicago, a handful of men gathered around a controlled laboratory in which they had carefully arranged a pile of wooden timbers and uranium bricks. Throughout the morning, these scientists had been ever-so-slowly pulling cadmium rods out of the pile, taking careful measurements of the result. Finally, at 3:25pm the men saw the reaction for which they had been looking; with the tension relieved, one of the scientists shouted in triumph, “We’re cooking!” No, this isn’t a joke about physicists boiling a pot ofwater; this is but a glimpse into the dawn of the nuclear age. For these scientists, the top minds in their field, had created the world’s first controlled, self-sustaining nuclear chain reaction, thrusting humankind into the nuclear age and changing the course of history.

Yet, while these men, fervently working to construct a nuclear bomb, had been charged by their country with the defense of the free world, the exact effects of the nuclear radiation upon human physiology were as of yet unknown. There was needed a man who understood something about these effects and who could monitor and perhaps protect these scientists from the deadly consequences of exposure to the radioactive material they were attempting to harness.That man was Dr. Leon Jacobson, a native son of Sims, North Dakota.

Long before his involvement with the Manhattan Project, Dr. Jacobson had served as a resident at the University of Chicago’s research hospital, where he gained considerable expertise examining the possible benefits of radiation therapy. Jacobson showed great promise in his early work, and after others in his department moved on to other research universities, Jacobson was put in charge of hematology, the study of blood.

Experts involved in the Manhattan Project were likewise aware of the possible effects of radiation upon the human body, and knew that it must be monitored if the scientists in charge of nuclear development were to be kept safe. Knowing Jacobson’s expertise, the government hired him in February 1942 to monitor the biological effects of nuclear experimentation and to watch over the health of the physicists building the ‘bomb.’ It was thus that a North Dakota farm-boy became a crucial component of the greatest scientific experiment in human history.

Dakota Datebook written by Lane Sunwall


Eugene Goldwasser, Almont North Dakota Centennial Website, [accessed, Nov. 01, 2011], http://www.sims-almont.us/History/Jacobsontribute.html

Madeline Marget, interview with Dr. Leon Jacobson, February 28, 1992, [accessed, Nov. 01, 2011], http://www.hematology.org/Publications/Legends/Jacobson/1619.aspx

National Archives & Records Administration, Manhattan Project Notebook, [accessed, Nov. 01, 2011], http://www.ourdocuments.gov/doc.php?flash=true&doc=77

New York Times, Obituaries, [accessed, Nov. 01, 2011] http://www.nytimes.com/1992/09/22/obituaries/leon-jacobson-81-physician-for-team-that-built-a-bomb.html

North Dakota Office of the Governor, Rough Rider Awards, [accessed, Nov. 01, 2011], http://governor.nd.gov/rough-rider/dr-leon-orris-jacobson

The U.S. Department of Energy, The History of Nuclear Energy, [accessed, Nov. 01, 2011] http://www.ne.doe.gov/pdfFiles/History.pdf

This text and audio may not be copied without securing prior permission from Prairie Public.

Dakota Datebook is a project of Prairie Public, in partnership with the State Historical Society of North Dakota, with funding from the North Dakota Humanities Council.

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