Los Alamos, 1943: the mesa that became the atomic city

In 1943 the federal government took over a mesa in northern New Mexico, closed the boys' school that stood on it, pushed out the families who homesteaded there, and built a secret city to design the atomic bomb. Los Alamos County, now an American World War II Heritage City, was a home front unlike any other. This Park Service lesson tells its story three ways: through the history of the land, a homesteader's granddaughter who grew up behind the fence, and a young soldier who helped test the first bomb.

The land before the laboratory

Los Alamos sits on the Pajarito Plateau in the Jemez Mountains. People have lived there for about 12,000 years. Pueblo people built villages on the plateau between about 150 and 1600 CE, then moved to year-round pueblos along the Rio Grande. During the Pueblo Revolt of 1680 against Spanish colonisers, some took refuge again in the old plateau sites and the cavates — rooms carved into the soft volcanic tuff. Into the late 1800s and early 1900s, Pueblo, Athabaskan and Hispanic people used the plateau for hunting, gathering and grazing.

The takeover

The isolated, fortress-like mesa was easy to secure. Its taking forced out Pueblo people and Anglo and Hispanic homesteaders. The school's buildings became bachelor quarters, a recreation room, a library, a nursery school and a fire station; its icehouse was later where the world's first nuclear device was assembled.

Who came, and who worked

• Scientists, recruited by Oppenheimer, under a contract between General Groves and the University of California, which ran the laboratory, supplied scientists and administrators, and handled civilian non-scientific jobs.
• Special Engineer Detachment (SED) soldiers, from October 1943 — 1,800 by August 1945.
• Women's Army Corps (WAC) members, peaking at 260 in August 1945, in almost every department: researchers, librarians, clerks, telephone operators, hospital technicians, cooks and drivers, many handling highly classified material.
• Hispanic and Pueblo workers from the area: men in construction, driving, carpentry and gardening; women as maids and in childcare.

No evidence has been found of African American workers at Los Alamos before 1947. Black scientists did research on nuclear reactions for the project at the Chicago Met Lab and at Columbia University and sent their findings on; why none worked at Los Alamos is not known.

Months of experiments — implosion tests at sites such as Q-Site and K-Site, and a firing site (L-Site) to study what was left of test devices — led to "the Gadget," the first atomic device, detonated at the Trinity Site on July 16, 1945.

Growing up behind the fence

Dr. Julia Maestas's grandfather, Manuel Sabino Maestas, homesteaded about 80 acres on the mesa, with a pond, timber, sheep, horses, cows and a stone house; the family summered there and wintered in San Pedro. He had no paperwork the family could trace, so when the government later paid compensation for the homesteads, they could not claim it.

Her father went to work at Los Alamos in 1942 as a civil guard for the Army Corps of Engineers and stayed some 35 years, later as a laborer and then a supervisor with the Zia Company; her mother was a maid at the Army hospital by Ashley Pond. In her oral history Maestas remembers a small L-shaped Quonset hut with outdoor latrines and no running water; learning English from a friend, as a Spanish-speaking girl; being embarrassed at school by a word she had never heard, "chore"; windows rattling from explosions that nobody explained; and being fingerprinted and badged, even as a small child, to pass the guards each week. Her father never spoke about his work.

A soldier's view

Benjamin Bederson (1921–2023) served in the Special Engineer Detachment at Oak Ridge and Los Alamos in 1944–45, was sent to Tinian, the island the atomic-bomb missions flew from, and later became a physics professor. In a memoir written 55 years later he recalled how the head of the explosives division, the Harvard chemist George Kistiakowsky, called the soldiers together and explained the whole project — fission, critical mass, implosion — contradicting the legend that everyone knew only their own piece.

Bederson's job was Jumbo: a steel cylinder 10 feet across and 25 feet long, with walls 14 inches thick, weighing 200 tons and costing $12 million, meant to contain the plutonium if the Trinity test fizzled so it could be recovered. He described barracks of 50 men, coal stoves stoked before dawn, and soldiers paid far less than the civilians working beside them. When his close friend was killed in the Battle of the Bulge, he wrote, it put those complaints in perspective.

For the classroom

Essential question: how did Los Alamos County develop as a home front city, and what did it mean for the people who lived there or were brought there?

• Describe the land and its people before and during the Manhattan Project.
• Explain the effect of choosing Los Alamos on those already living there.
• Identify who was recruited or brought in, why they came, and what their lives were like.
• Extensions: the Kwage Mesa Trail wayside markers, and African Americans in the Manhattan Project.

The lesson is part of the Park Service's Teaching with Historic Places series on the World War II home front.

Sources

Written from "(H)our History Lesson: The Development of the Manhattan Project in Los Alamos County, New Mexico, WWII Heritage City," National Park Service, with a background reading by Sarah Nestor Lane; a work of the United States government in the public domain. It draws on an oral history interview with Dr. Julia Maestas (interviewer Willie Atencio) and Benjamin Bederson's "SEDs at Los Alamos: A Personal Memoir," both described rather than reproduced here.