(H)our History Lesson: The Development of the Manhattan Project in Los Alamos County, New Mexico, WWII Heritage City

Aerial view of the Los Alamos site in 1950.

Los Alamos National Laboratory, Department of Energy.

About this Lesson

This lesson is part of a series teaching about the World War II home front focused on Los Alamos County, New Mexico, designated as an American World War II Heritage City. The lesson contains photographs, a background reading, and interview and memoir excerpts to support learners’ understandings about the home front contributions of Los Alamos and the people who lived there. It explores the history of the land and its people, along with sharing perspectives from a child who grew up there and a soldier stationed there. Extension activities include examining a local trail’s markers and learning about African Americans and their contributions to the Manhattan Project.
To see more lessons about World War II, visit Teaching with Historic Places.

Objectives:

1. Describe the history of the Los Alamos County Land and its people prior to and during the Manhattan Project era.
2. Explain and reflect on the impact of the selection of Los Alamos County on the people living there.
3. Identify those who were recruited or asked to move to Los Alamos County, and their reasons for doing so, along with describing examples of their experiences.

Materials for Students:

1. Photos 1- 5 (can be displayed digitally)
2. Readings 1, 2, 3 (one secondary; two primary)
3. Recommended: Los Alamos Map by Manhattan Project National Historical Park and Technical Areas Map by Los Alamos Neutron Science Center
4. Extensions: 1) Kwage Mesa Trail Wayside Markers, 2) African Americans and the Manhattan Project

Getting Started: Essential Question

How did Los Alamos County, NM develop as a home front city, and what was the impact on those who lived or moved there?

Read to Connect

Teacher Tip: Reading 1 can be used as the foundation for understanding the land and its background. To shorten the lesson, students can be divided into groups to read either Reading 2 or Reading 3, and then share a summary of the findings and perspectives from the interview and memoir.

Reading 1: Los Alamos County

Reading 1: Los Alamos County  

By Sarah Nestor Lane 

Los Alamos County, New Mexico is a Manhattan Project site. This project developed the atomic bomb in World War II. The history and development of the area is complex. 

The History of the Land and its People 

Los Alamos is on the Pajarito Plateau in the Jemez Mountains and is an Ancestral Pueblo Site. Native people settled and lived in this area for thousands of years, dating back to around 12,000 years ago. Pueblo people built villages between 150 and 1600 CE (common era) on the plateau. After the mid-1500s, people stopped living there year-round. They began building pueblos, an adobe architectural style named for its builders, along the Rio Grande. In 1680, the Pueblo people rebelled against the colonizing Spanish. Some sought refuge on the plateau’s ancestral sites. These places offered natural protection. Pueblo people carved cavates, dwellings in tuff cliffs for shelter. Different groups, including the Pueblo, Athabaskan, and Hispanic people, continued using the plateau. They used it for hunting, gathering, and grazing during the late 19th and early 20th centuries. This was before and after New Mexico became a state in 1912. 

World War II: Construction and Development 

During World War II, the US government took over the land in this area to develop it as a site for the Manhattan Project. The Manhattan Project was created to develop the atomic bomb. The government’s development of Los Alamos for the research laboratory led to the forced displacement of people from the land. This included Pueblo people and Anglo and Hispanic homesteaders.  

General Leslie Groves appointed J. Robert Oppenheimer, a physicist, in the spring of 1942 to work on the Manhattan Project. He was familiar with the Los Alamos area, having a ranch nearby. The isolated area was easier to keep secure and was fortress-like. Government knowledge and reports from the area led to the final selection of Los Alamos for the Manhattan Project site.  

At Los Alamos was the Los Alamos Ranch school, a boys only school, founded during World War I in 1918. Ashley Pond Jr. established the school. The school had strict discipline and rigorous academics. General Leslie Groves took over the school grounds by using the War Powers Act of 1941. This resulted in the closure of the school in January 1943. General Groves directed the construction at Los Alamos. Construction started after the federal government acquired the land. School facilities shifted to be bachelor quarters, a recreation room, library, nursery school, and a fire station. The icehouse was later used as a building to assemble the world’s first nuclear device. Newly constructed military and laboratory buildings included an administration building, utilities, and technical buildings.  

Scientist and Worker Recruitment 

Oppenheimer recruited scientists to work at the laboratory in Los Alamos. General Groves contracted the University of California for the Labatory. The contract with University of California helped with recruitment and procurement of resources. It contributed by hosting a laboratory, produced scientists and administrators, and also contracted with the US Army to administer civilian, non-scientific roles. Oppenheimer was one of the staff members of this university. Additionally, Special Engineer Department troops began arriving in October 1943. A total of 1800 worked at Los Alamos by August 1945.  

Recruited scientists and university staff worked at the labs constructed at Los Alamos to develop nuclear bombs. However, African American scientists did not work at Los Alamos. African American scientists conducted research on nuclear reactions at the Chicago Met Lab and Columbia University. They provided findings to Manhattan Project scientists at other sites, like the Los Alamos Labatory. Some say there were not African Americans at Los Alamos because there were few Black atomic scientists for Oppenheimer to recruit, but exact reasons are unknown. As of right now, there is no evidence found of African Americans working at Los Alamos before1947.  

Women’s Army Corps members (WACs) served at Los Alamos, with a peak of 260 WACs in August 1945. WACs were involved with almost all departments. Roles included scientific researchers, librarians, clerks, telephone operators, hospital technicians, cooks, and drivers. Many roles involved handling highly classified material.  

Native American and Hispanic people worked at Los Alamos too. The Los Alamos site managers hired many local Hispanic, Spanish-speaking, and Pueblo people as maintenance and custodial workers. Men worked in construction, as truck drivers, carpenters, and gardeners. Women worked as maids and provided child-care. 

The Atomic Bomb 

Many tests at Los Alamos labs included experiments to understand implosions. Scientists completed tests at sites like Q-Site and K-Site. Another example was the L-Site, a firing site to study bomb remains. There were other important locations at Los Alamos. These provided space to construct and assemble components and conduct tests and research. Labatory scientists had to work across buildings and sites to find solutions. Months of research and tests resulted in "the Gadget." The Gadget was the first atomic device. Scientists detonated it on July 16, 1945, at the Trinity Site. 

Reading 2: Interview with Dr. Maestas (Excerpts)

Interview with Dr. Julia Maestas (excerpts) 

Background: Dr. Julia Maestas’ grandfather was a homesteader who lost his land when the federal government took it for the Los Alamos laboratories. Her father worked as a civil guard for the Corps of Engineers. She grew up and went to school in the area. The interview is courtesy of the Atomic Heritage Foundation, Voices of the Manhattan Project. 

Dr. Julia Maestas: . . . My grandfather was Manuel Sabino Maestas, and he homesteaded up at Los Alamos. He had, as I understand, about eighty acres up there. He made a pond up there. He had timber, and he had sheep, and he had horses, and he had cows. He built a house of stone up there. 

My father lived up there. My cousin, Adele Tometich, who now lives in Santa Fe, lived up there. I understand that they lived up there during the summer. Then they came down here and lived in San Pedro during the wintertime. 

That’s pretty much all I know except that Grandpa never had any paperwork that we could follow. Therefore, when the homestead reimbursement, or compensation, or whatever it was, came to be, I didn’t have the appropriate paperwork for that. 

So, the family was not eligible for it. Which is really sad, because my cousin, Adele, who is now eighty-three or eighty-four, lived there during that time and remembers quite a bit more than I do. Of course, I didn’t know anything about it. But, anyway, that’s where my grandfather was. . . . 

Daddy went up to Los Alamos. Apparently, he worked there for thirty-four years. He first went there in 1942, and he was “a civil guard with the Army Corps of Engineers” until Zia [Company] was developed or formed in 1946. 

Willie Atencio, interviewer: Civil guard for the Corps of Engineers. 

Maestas: Initially in 1942. Then in 1946, when Zia came about, he was a laborer there. Later on, he became a supervisor for the laborers. He worked there for thirty-five years. My mom worked at the hospital. 

Atencio: Your mother’s name, Eloisa? 

Maestas: . . . I can remember she was a maid up at the hospital. I can remember visiting her there in the hospital. It was an Army hospital next to Ashley Pond. . . . 

Atencio: During the war, do you remember what your father did while he was a civil guard? Did he ever talk about his work? 

Maestas: Never. 

Atencio: Your father never talked about his work? 

Maestas: Oh, no, and I was too little even if he had talked about it. I wouldn’t have understood. All I remember about living in that Quonset house was that the latrines were outside. We didn’t have running water inside. It was very small. It was an L shape. Then I had a really good friend by the name of Crystal. . . . I don’t have any ideas as to what her last name was or anything. Anyway, she became my really good friend. I think it was through her that I learned to speak English, because I was a Spanish speaker. . . 

Atencio: Okay. You went to school as a first grader in Los Alamos? 

Maestas: Well, as I was telling you before, I remember first going over there and that it was a room about this size. It looked like it was either a conference room or a library. It was not a “school.” I can remember there were tables. I can remember that the teacher for some reason – I was a Spanish speaking kid, and I can remember– 

Atencio: Do you remember the teacher’s name? 

Maestas: No. I can remember the teacher asking me what the word “chore” was. I’d never heard the word “chore” in my whole life. Apparently, it really embarrassed me, because I can still remember that I didn’t know the word “chore.” I think it really, really embarrassed me, but I didn’t know English. 

That’s all I remember except that it was a beautiful building. I think it was wood. I think it had a lot of books. It must have been either a library or conference room, and it must have been an Army building. . . . 

I can remember sitting in the school. There were explosives. They went boom. The windows would rattle. This happened frequently, but I can remember sitting there and looking out of this window after the boom of whatever was happening, but that’s all I remember about anything. Nobody talked about it, because it was all so secretive. 

Atencio: Did you have a badge to get into town? 

Maestas: Yeah, we all did. We had to stop, even children. They fingerprinted us, and they gave us whatever. Because we used to live in Los Alamos during the week and down here in San Pedro during the weekends, we’d go back and forth. 

I can remember having to stop there, and they would check us out. I think I could even remember being fingerprinted, but I was really small. I can remember the guards up in the tower. I haven’t thought about any of this for years. 

Excerpt 3: Bederson Memoir (Excerpt)

Reading 3:  Memoir (Excerpt) 

Teacher Tip: You may wish to show this video of “Jumbo” for students to better understand and visualize the device described by Bederson in his writing. Jumbo was a steel cylinder 10 feet in diameter and 25 feet long that cost $12 million. Its walls were 14 inches thick and the entire device weighed 200 tons. 

Background: Benjamin Bederson (1921-2023) was an enlisted soldier in the U.S. Army’s Special Engineering Detachment (SED) in Oak Ridge, TN and Los Alamos in 1944—1945. He spent time on Tinian Island, the launching point of the atomic bombs dropped on Japan. He discharged in 1946 and 55 years later, wrote his personal memoir. He went on to finish college and graduate school, becoming a professor of physics. 

“SEDs at Los Alamos: A Personal Memoir” (Excerpt) 

By Benjamin Bederson 

In a month or two I was called to a small meeting of SEDs who like myself were working on various aspects of explosives. At the meeting we were greeted by the head of the Explosives Division, George B. Kistiakowsky. ‘‘Kisty’’ was a professor of chemistry at Harvard, one of the most distinguished chemists in the world, as I was to find out later. He had a strong Russian accent, and was very approachable and good-natured. The purpose of the meeting was to let the GIs know what was going on at Los Alamos. He layed it all out, from beginning to end. The story that circulated later about how security was so tight on the Manhattan Project that people only knew exactly what they needed to know to do their job was simply untrue. He explained nuclear fission, critical mass, and the implosion concept among other things. 

None of this was needed for my job, which, it turned out, was to help create something called Jumbo. Jumbo was a huge cylindrical container into which was to be placed the first ‘‘Fat Man’’ to be tested. Fat Man was the name of the implosion bomb (generally referred to as the ‘‘gadget’’), and Jumbo was intended to contain the radioactive material if the nuclear explosion failed, but if the TNT explosive lenses would do enough damage to spread deadly radioactivity from the unfissioned plutonium. Jumbo was to prevent this radioactivity from spreading all over the landscape – and, incidentally, making it possible to recover the unspent plutonium for another try. That was why I was testing containers! Everything fell into place with Kistiakowsky’s revelations, from the mysterious distillation plants in Oak Ridge to the overwhelming secrecy of the entire project. The only thing I had cause to be miffed about was my faded hope that the Manhattan project would get me back to New York. Still, the thought that somehow I had landed in the middle of what was certainly a historic enterprise was exhilarating and inspiring. . . .  

All SEDs were assigned to a special barracks; other soldiers such as MPs and guards were quartered elsewhere. (When I arrived there was only one SED barracks, although a second was soon built.) There was an interesting dichotomy in our daily lives. While working in the Tech Area or elsewhere we were treated like the civilian workers, with privileges compatible to our jobs and responsibilities. However, at other times we were simply soldiers like all other soldiers, with a lieutenant in charge of the SEDs and a major in charge of all soldiers . . . 

But living in one large room with 49 other soldiers was hardly a pleasant experience. The latrines were public, as were the showers. Heat was supplied by two or three coal stoves per barracks, and these had to be stoked by volunteers, especially in the early morning when it tended to be very cold. I had to perform my share of this onerous chore. Of course none of us, including me, really resented our lot. We were all too well aware that there were soldiers fighting and dying while we had to suffer relatively unimportant inconveniences, while performing exciting and important work. Thus, our gripes were not taken very seriously, either by the Army or by ourselves. Probably the most serious complaint the SEDs had concerned relative rather than absolute treatment. Young civilians and SEDs (and even some Navy Ensigns) often worked side by side with comparable responsibilities, sometimes with SEDs ranking higher than civilians. But the civilians not only did not have to put up with Army discipline, they also were far better paid. This did not make very good sense to the GIs whose monthly checks often did not reach higher than two digits. In late spring of 1945 I received a letter from my father framed in black ink. He informed me that my close friend Irving Yusin, who had shared living quarters with me in Philadelphia for six months before I was drafted in 1942, had been killed in the Battle of the Bulge. This essentially trivialized my so-called hardships, putting them into the proper perspective of the year 1944.  

By the numbers:

• 8,900 acres of privately-owned land and 45,100 acres of federally owned land (Forest Service) requested for “the establishment of a demolition range” from the Secretary of War to the Secretary of Agriculture on March 22, 1943
• The federal government purchased the land area for the Los Alamos Manhattan Project site for about $415,000. Construction was completed in November of 1943 at a final cost of $7 million.
• Los Alamos in 1943: Approximately 100 scientists, engineers, and support staff lived and worked there.
• Los Alamos in 1945: 6,000 people lived there, with more than 4,000 of them working in the laboratories.

Quotation to consider:

“It is certainly with pride, and a deep feeling of gratitude to each one of you, that I send this message. The security measures that still involve the Manhattan District Project, the great responsibility that each one of you will always have, set you apart as very special and honored heroines in World War II. Your devotion to duty, the sacrifices you have made, the daily soldier privileges that you have forfeited, and your loyalty to the security measures necessary will be proudly recorded in the history of the Women’s Army Corps.”

- Westray Battle Boyce, Director, Women’s Army Corps, letter to the WACs, dated September 6, 1945.

Student Activities

Activity 1:

Review Reading 1, along with the "By the Numbers," "Quotation to Consider" and Photos 1-3. Then answer the following questions.

1. Why were Native American and Hispanic individuals moved from land in the Los Alamos region?

2. Think about the Los Alamos Ranch School changing from a school to a place where they built the first nuclear bomb in World War II. How did this shift show what the government thought was important during that period?

3. Explain why there may have been no African American scientists at Los Alamos before 1947. Think about the history at that time and what things might have affected this situation.

4. Who, and what work, in Los Alamos County contributed to the home front efforts that led to eventual victory in World War II?

Dr. Julia Maestas, who grew up at Los Alamos. She is pictured here as a young woman. In this lesson you can listen to her oral history, recorded in 2022.

Atomic Heritage Foundation. Copyright 2017 Willie Atencio and David Schiferl.

Activity 2:

Review Reading 2, then answer the following questions.
Additional Background: Many Hispanic families and homesteaders in the area were Spanish-speaking, and children began to attend the English-speaking schools with children of those who moved to the area for the Los Alamos laboratories.

1. How was Dr. Maestas’ grandfather and family impacted by the development of Los Alamos County?

2. What memory does Dr. Maestas have of her experience at school in Los Alamos as a first grader? Why may this stand out to her?

3. Think about Dr. Maestas' memories of explosives and fingerprints, along with the secretive community. What are some emotions you think children growing up in Los Alamos may have had?

Activity 3:

Review Reading 3 and Photos 4-5. Then answer the following questions.

1. Why were “Kistiakowsky’s revelations” meaningful to the author?

2. What was the purpose of the container called "Jumbo" in relation to the first "Fat Man" test? How did the author contribute to the project?

3. Examine the difficulties that soldiers like the author encountered at Los Alamos on the home front and contrast them with the challenges faced by soldiers overseas. How were their experiences unique, and what shared aspects connected their stories?

Optional discussion

If students read texts in separate groups:
Students share their summaries, using the reading questions as a guide for their summaries, and then engage in discussion to compare the experiences of Dr. Julia Maestas (Reading 2) and Benjamin Bederson (Reading 3).

Extension Activities

Kwage Mesa Trail Wayside Markers

The Kwage Mesa trail, managed by Los Alamos County, is located on the Pajarito Plateau. It overlooks Bayo Canyon, where testing was done for the Manhattan Project. Use the following images and descriptions of the wayside markers to better understand the history of the land and its development. Compare the information from the markers to what has been learned in the readings on Los Alamos County so far.  

If time allows, students may design their own wayside that they feel would contribute to the understanding of the place’s history.  

• An Explosive History   

• A Volcanic Landscape  

• Pueblo Communities  

• Hispano Communities 

• Now We Have Our Bomb 

• Cleaning Up Bayo Canyon 

Teacher References: Planning and creating Wayside exhibits 

• Wayside Exhibits: A Guide to Developing Outdoor Interpretive Exhibits (Wayside Guide)  

• Wayside Planning - by Harpers Ferry Center   

African Americans and the Manhattan Project 

“The existence of Black atomic scientists within a culture which denied Black men’s intellect demonstrated the possibilities of science as an egalitarian career. That there were so few was a testament to the structural racism of American education.”  

-Shane Landrum, historian* 

African American scientists and workers were not at the Los Alamos site. As Landrum describes, there were layers of discrimination and racism across many contexts that contributed to the lack of African American scientists at Los Alamos. However, Black scientists contributed to the Manhattan Project at Hanford and Oak Ridge, and scientists contributed at smaller sites such as in New York and Chicago.  

Select a scientist’s profile from “African Americans – Manhattan Project National Historical Park” and share a summary of the person’s contributions. 

Other resources include:  

• “African Americans and the Manhattan Project;” Ruffin, Taylor, and Mack, Freedom’s Racial Frontier 

• African Americans and the Manhattan Project - Nuclear Museum 

• African Americans at Los Alamos and Oak Ridge: A Historic Context Study (nps.gov) 

• African-Americans and the Manhattan Project - Ranger in Your Pocket, Nuclear Museum 

Note: Shane Landrum, “‘In Los Alamos, I Feel Like I’m a Real Citizen’: Black Atomic Scientists, Education, and Citizenship,” (master’s thesis, Brandeis University, 2005), 2 

Additional Resources

NPS Resources

• Before and After - Manhattan Project National Historical Park (U.S. National Park Service) (nps.gov)
• Fuller Lodge (U.S. National Park Service) (nps.gov)  

Other Resources

• A history of Los Alamos, New Mexico (nmt.edu) 
• Civilian Displacement: Los Alamos, NM | Atomic Heritage Foundation 
• Dick Skancke (Manhattan Project Security Guard) discusses Security Checks - Video 
• Los Alamos, NM - Ranger in your Pocket 
• Manhattan Project: Places > LOS ALAMOS: THE LABORATORY (osti.gov) 
• "Sense of Place" Los Alamos Documentary Video (24:45) 
• The Women's Army Corps at Los Alamos— The Manhattan Project - Video 

This lesson was written by Sarah Nestor Lane, an educator and consultant with the Cultural Resources Office of Interpretation and Education, funded by the National Council on Public History's cooperative agreement with the National Park Service.