Manhattan Project

David W McBride. Encyclopedia of Leadership. Editor: George R Goethals, Georgia J Sorenson, James MacGregor Burns. Volume 3. Thousand Oaks, CA: Sage Reference, 2004.

The Manhattan Project was a secret U.S. military engineering project undertaken during World War II to develop the world’s first atomic bomb. Lasting from 1942 to 1946, it was carried out under the tight supervision of the U.S. military and government and combined thorough scientific research and industrial engineering. The project was conducted so secretively that Vice President Harry Truman was unaware of it until after he was sworn in as president upon the death of President Franklin D. Roosevelt in 1945. The man in charge of the project was Gen. Leslie Groves. Groves, born 17 August 1896, was the deputy chief of construction of the U.S. Army Corps of Engineers. His engineering and military background gave him the necessary experience to head the project. Groves would oversee the project throughout, proving to be a capable and determined leader. His leadership was best exemplified by his obsession with completing the task. His primary concern with the Manhattan Project was to get fast and effective results without jeopardizing the secrecy of the project, and his aggressive and assertive leadership style was exemplified by his relentless pursuit to create the atomic bomb. Although many of the scientists who worked under Groves found him to be offensive and intimidating, the greatest secret military project in modern history would be a success, with its scientists and engineers able to develop the first atomic bomb under immense pressures.

At the beginning of the Manhattan Project, research was being conducted at many universities throughout the country, but under Groves’s attention, research would be condensed to three main sites. The most famous of these sites was Los Alamos, New Mexico, where under the supervision of its director, scientist J. Robert Oppenheimer (1904-1967), the bomb was designed and constructed. At the project’s peak, more than 130,000 people were working on the project. The Manhattan Project marked the first time that the fields of industry and science had worked together with government on a major project. Thus, the interaction between the military officials and the scientists was crucial to success. At Los Alamos, the developers and researchers worked together in a tight-knit community while remaining isolated from the outside world because secrecy was a top priority. Under such arduous conditions, strong leadership and organization were vital. Both Oppenheimer and Groves would prove to be men capable of handling the most difficult of tasks under the most stressful times.

The Birth of the Manhattan Project

The first indications of the possibility of atomic energy became evident in 1938 in Berlin, with the splitting of the first uranium atom. On 11 October 1939, U.S. physicist Albert Einstein wrote to President Roosevelt to tell him that the Germans were probably attempting to construct an atomic bomb. A receptive Roosevelt ordered the formation of a committee whose purpose was to finance U.S. universities in uranium research. By December 1941 research had begun on the properties of fissile materials, which were crucial for the explosion of the atomic bomb. Much of the research was done at the Metallurgical Laboratory at the University of Chicago.

This research was handed over to the U.S. Army Corps of Engineers in June 1942. On 17 September 1942, General Groves was placed in charge of the project and promptly named the project the “Manhattan Engineering District,” which would become more commonly referred to as the “Manhattan Project.” His main task was to carry out the project as quickly and as secretively as possible so that other countries would remain unaware of it. This was a difficult task because the project was spread out across the country and because to complete the project’s objective Groves had to ensure that the people working on the project were unaware that their research was intended to produce an atomic bomb. His plan was to carry out the project in an industrial format, with the military, rather than the scientists, governing. This format was alien to the scientists, who believed that at all times they should be the authoritative figures of their research.

Groves’s organizational strategy was known as “military compartmentalization.” The scientists were assigned to individual groups with separate tasks. A military advisor would oversee each group, ensuring that the scientists could communicate information only to this advisor. This strategy eliminated the free flow of information that was commonplace during scientific research. As a result, the scientists were unable to determine that their individual assignments were part of the grand scheme of building the bomb. Compartmentalization was successful in that it kept the project a secret; however, under such conditions the scientists found work difficult.

In his labs at the University of California at Berkeley, Oppenheimer was placed in charge of the theoretical design project in the spring of 1942. During the summer of 1942 he supervised a group of theorists, including Edward Teller, whose purpose was to decide how to create an atomic bomb. Scientists had many uncertainties regarding how to cause the most effective and powerful atomic explosion. They determined that although achieving results would take a tremendous effort, it was possible, and they proposed a few hypothetical methods to create the necessary explosion. These methods would be the basis of the research at Los Alamos, which is significant in that the entire project was based on untested theories.

The Test Sites

One of Groves’s greatest leadership assets as overseer of the project was his ability to recognize problems and make adjustments. He was aware that their being spread across the country made progress difficult for the workers. To alleviate this difficulty, one of his first decisions was to purchase land in Oak Ridge, Tennessee, which would be used for uranium research. Oppenheimer was also aware of the problem, especially for the scientists who could not work effectively without being able to access information from one another. In their isolated groups, Oppenheimer believed, the scientists were wasting valuable time trying to relay information to one another. Under these circumstances, the decision to create a private site solely for the scientists was approved. Groves chose Oppenheimer to be the scientific director of the project in November of 1942. Some people wondered if Oppenheimer would be a successful leader. Groves and Oppenheimer nevertheless agreed to use an isolated boys’ ranch at Los Alamos, New Mexico, as the site for scientific research. By April 1943, the ranch was ready for the scientists, whose sole objective was to create an atomic bomb.

On 2 December 1942, the project received a major breakthrough. After three years of research, Enrico Fermi (1901-1954), a renowned scientist at the metallurgical labs in Chicago, produced the first sustaining uranium chain reaction. The significance was that both uranium and plutonium could be potential materials for the atomic bomb. Based on Fermi’s discovery, the Manhattan Project directed its attention to creating large amounts of both materials. A third test site was built at Hanford, Washington, where the engineers’ task was to produce large amounts of plutonium.

The idea to create three test sites was a major boost for the project. The solution for the scientists was simple: consolidate all of the scientists into one isolated location where they could work among their peers and freely exchange information yet remain in secrecy from the rest of the world. In February 1943 construction began at Oak Ridge, where the scientists faced the daunting task of separating the uranium isotope U-235 from natural uranium. The workers remained unaware that they were contributing to construction of the atomic bomb. Two months later, construction began at Hanford. Groves chose to have the Hanford site supervised by both his army engineers and the du Pont corporation, which was responsible for assembling the plant at Hanford where research would be conducted. Groves chose du Pont because of its ability to construct a functioning plant in a short period of time. When he approached du Pont with his proposition, Groves never disclosed the fact that du Pont would be helping to create a bomb to be used to end the war. Rather, he gave du Pont only information relative to its assignment, which was consistent with his belief that with few exceptions, the workers needed to know only what their task was, leaving the overall objective to himself and his advisors to oversee.

Los Alamos

The assignment at Los Alamos was named “Project Y,” and its task was to develop the bomb. The men and women at Los Alamos were scientists, civilian engineers, metallurgists, and military officials. Many different backgrounds and personalities had to be blended as one team for the project to produce quick and effective results. The University of California was contracted by Groves on 15 April 1943 to conduct the research under Oppenheimer’s supervision. Oppenheimer’s task was to supervise the technical and scientific work. All information would pass to him, and then he would report back to Groves. The decision to allow the scientists to work together in an isolated camp addressed two important purposes. First, it produced an environment conducive for scientific work because scientists could exchange important information easier. Second, the scientists remained isolated from the general public, thus preserving the project’s secrecy.

In April 1943, Oppenheimer briefed his first group of scientists at Los Alamos, telling them that their task was to construct an atomic bomb. He told them of the recent discoveries in fast-fission research, and by the end of the briefings the scientists were up to date with the project. To most of the scientists, the enormous task of creating an atomic bomb brought a much-needed enthusiasm to the work, an enthusiasm that had been suffocated by military compartmentalization. Ensuring that the scientists were excited and intrigued by the challenges of their work was important to Oppenheimer. The scientists were informed of the various potential experiments relating to their work, which was mostly based on theories rather than fact. Their work would be unprecedented, and the scientists readily accepted the challenges.

Early Problems in New Mexico

In an effort to make the workers more comfortable, their families were allowed to live with them for the duration of the project. However, problems at Los Alamos surfaced early because on-site housing facilities were not ready for everyone. Alternative living areas were provided at ranches in Santa Fe, but these proved to be overcrowded and poorly equipped. Transportation to and from the test site was equally as burdensome, with too few vehicles to transport everyone. Because of the need to begin the project quickly, the workers had to endure dismal conditions and focus on their tasks.

To counteract the housing problems, Oppenheimer was determined to make the working environment as conducive to scientific research as he could. Under his supervision the laboratory and its two hundred scientists were broken into five groups, each with its own set of tasks. However, unlike in military compartmentalization, each group had a better outlet for the transfer of information between the other groups. Oppenheimer needed to keep the scientists focused on their individual research tasks because their work was the most challenging. Many of the scientists were working with plutonium, which was relatively new to the scientific field and whose properties remained unknown. In addition, acquiring the proper equipment immediately was often difficult, and thus scientists were often handicapped in their research.

Through all of these problems, Groves was relentless about the scientists pressing on. Groves expected problems to arise, but rather than wait for the problems to be resolved, he fiercely pressed the scientists to not only continue their work, but also to make positive findings in their work, no matter how disadvantaged they were. He refused to let the project slow down in fear that the Germans would produce a bomb first. Under such conditions, Oppenheimer was an effective leader. He was not an aggressive or intimidating leader, and as a scientist he was able to relate to the problems the other scientists faced. He made sure that Los Alamos was organized as a civilian laboratory, as opposed to Groves’s initial plan to organize Los Alamos as a strict military-run laboratory. One of Oppenheimer’s greatest virtues was his ability to have a good relationship with both Groves and the other scientists, thus allowing him to bridge their differences. A more aggressive director would have only added to the problems that the scientists already faced. Oppenheimer embodied the leadership skills necessary for the situation that he faced. His greatest gift as a leader was his ability to meet the situational demands that he encountered at Los Alamos.

Research at Project Y

The main research problem confronting the scientists was finding a way to sustain a neutron chain reaction. The more neutrons released during a chain reaction, the greater the explosion of the bomb. The difficulty lay in trying to release the most neutrons before the bomb exploded. As neutrons were released, the energy that they produced could cause the bomb to explode prematurely. The scientists had to find ways to prolong the time before the bomb exploded to enable more neutrons to be released.

By the spring of 1944, small amounts of plutonium had arrived at Los Alamos for experiments. The properties of plutonium continued to confuse and frustrate the scientists. Its unpredictability caused the scientists to have to rethink part of their research. Previously the scientists had concluded that the best type of bomb would use the gun-assembly method, which worked by shooting one fissionable material into another. This would produce the explosion needed to explode the bomb. With regards to plutonium, the scientists were skeptical that the gun-assembly method would cause an explosion. They needed a new way to cause the plutonium to explode, and so they focused their attentions to the idea of implosion.

The theory behind implosion was that instead of shooting the particles into one another, implosion directed the blast inward, where large amounts of fissionable materials would squeeze themselves together until they caused an explosion. The problem with implosion was that, unlike the gun-assembly method, it had never previously been attempted. By July 1944, finding a way to use implosion became the top priority at Los Alamos. However, even with much attention being put into plutonium implosion, results were slow.

Alamogordo and the Trinity Test

Groves and Oppenheimer had first begun discussing the notion of a test in the spring of 1944. Both men were confident that the gun-assembly bomb would work, but doubts lingered over the plutonium implosion-type bomb. The uranium bomb was constructed in May 1945 and needed only enough uranium. On 13 July, the implosion-type bomb was built, although no one knew whether it would work. By testing the plutonium bomb, the scientists could see if their design had faults.

Scientists had two concerns over the test. The first involved simply whether the bomb would explode. The second involved the weather and the potential radioactive fallout if the bomb did explode. The test was conducted in the desert to be far from human population, but because the after-effects of the bomb were unknown, Groves had vehicles ready in case he needed to evacuate civilians who were unaware of the test. At 5:30 A.M. on 16 July 1945, the first atomic bomb, named “Gadget,” was detonated in the deserts of New Mexico. Scientist Kenneth Bainbridge was given the role of test director and spent over seven months preparing for the test.

When the bomb was detonated, its explosion filled the sky. The test proved that the implosion bomb would work. Witnessing the explosion, both Oppenheimer and Groves knew that they had effectively helped to win the war. Although the explosion was greater than expected, there was no danger of radioactive fallout. The test symbolized the triumph of the most organized and important national project of the century. Twelve months earlier the idea of creating an implosion-type bomb was thought impossible. The Manhattan Project had proved this assumption wrong.


The creation and detonation of the atomic bomb led to the end of World War II. A uranium bomb, Little Boy, and a plutonium bomb, Fat Man, were dropped on Japan on 6 August and 9 August 1945, respectively. On 2 September 1945, Japan formally surrendered aboard the USS Missouri.

Although Oppenheimer has been called “father of the atomic bomb,” General Groves deserves the primary credit. The Manhattan Project was not simply a scientific operation, but rather was foremost an engineering operation that combined science and engineering to create the atomic bomb. Groves was the man who oversaw every aspect of the project, and his determination to develop the bomb was the driving force. He died on 13 July 1970.

The success of the Manhattan Project was a vindication of the effective leadership of both Groves and Oppenheimer. Each man was a capable leader in his own right, and although they differed in their leadership styles, they proved to be an effective team. Groves’s relentless pursuit of excellence kept the project focused. Oppenheimer’s understanding of the circumstances that the scientists faced allowed him to create an atmosphere most suitable for scientific research.