The expanding federal bureaucracy also had a human face. To fight the war, the government mobilized tens of millions of soldiers, civilians, and workers — coordinated on a scale unprecedented in U.S. history. During World War II, the armed forces of the United States enlisted more than fifteen million men and women. In no other military conflict have so many American citizens served in the armed services. They came from every region and economic station: black sharecroppers from Alabama; white farmers from the Midwest; the sons and daughters of European, Mexican, and Caribbean immigrants; native men from Navajo and Choctaw reservations and other tribal communities; women from every state in the nation; even Hollywood celebrities. From urban, rural, and suburban areas, from working-class and middle-class backgrounds — they all served in the military.

In contrast to its otherwise democratic character, the American army segregated the nearly one million African Americans in uniform. The National Association for the Advancement of Colored People (NAACP) and other civil rights groups reprimanded the government, saying, “A Jim Crow army cannot fight for a free world,” but the military continued to separate African Americans and assign them menial duties. The poet Langston Hughes observed the irony: “We are elevator boys, janitors, red caps, maids — a race in uniform.” The military uniform, Hughes implied, was not assigned to African Americans so readily. Native Americans and Mexican Americans, on the other hand, were never officially segregated; they rubbed elbows with the sons of European immigrants and native-born soldiers from all regions of the country.

Among the most instrumental soldiers were the Native American “code talkers.” In the Pacific theater, native Navajo speakers communicated orders to fleet commanders. Japanese intelligence could not decipher the code because it was based on the Navajo language, which fewer than fifty non-Navajos in the world understood. At the battle of Iwo Jima, for instance — one of the war’s fiercest — Navajo code talkers, working around the clock, sent and received more than eight hundred messages without error. In the European theater, army commanders used Comanche, Choctaw, and Cherokee speakers to thwart the Nazis and exchange crucial military commands on the battlefield. No Axis nation ever broke these Native American codes.

Approximately 350,000 American women enlisted in the military. About 140,000 served in the Women’s Army Corps (WAC), and 100,000 served in the navy’s Women Accepted for Volunteer Emergency Service (WAVES). One-third of the nation’s registered nurses, almost 75,000 overall, volunteered for military duty. In addition, about 1,000 Women’s Airforce Service Pilots (WASPs) ferried planes and supplies in noncombat areas. The armed forces limited the duties assigned to women, however. Female officers could not command men, and WACs and WAVES were barred from combat duty, although nurses of both sexes served close to the front lines, risking capture or death. Most of the jobs that women did in the military — clerical work, communications, and health care — resembled women’s jobs in civilian life.

Historians still debate how to characterize the World War II American military. As an army of “citizen-soldiers,” it represented a wide stratum of society. Military service gave a generation of men a noble purpose, following a decade of economic depression. And its ethic of patriotism further advanced the children of immigrants into mainstream American life. Yet the military embodied the tensions and contradictions of American society as well. The draft revealed appalling levels of health, fitness, and education among millions of Americans, spurring reformers to call for improved literacy and nutrition. Women’s integration into the military was marked by deep anxieties about their potentially negative effects on male soldiers as well as the threat to “womanhood” posed by service. The American army was like the nation itself. United in wartime purpose, the military reflected the strengths and weaknesses of a diverse, fractious society.