Native American soldiers have made important contributions during all U.S. wars. But during the two world wars, Indigenous languages became the basis of a secret communications strategy that stumped enemy intelligence—and proved essential to winning key battles.

It began in 1918, when three enlistees from the Choctaw nation deployed to France were overheard by an officer speaking their native language. It sparked an epiphany: That language, so unknown outside their own small nation—and without a long written history—could be perfect for secret coded communications. Choctaw soldiers were quickly utilized as "phone talkers," delivering messages via field telephones, during World War I. And while the conflict ended soon after, their work shaped military communications going forward. During World War II, the strategy encompassed more than a dozen Native languages, most notably Navajo. That work became known as "code talking."

Ironically, the U.S. military was drawing benefit from languages that the U.S. government had long been working to eradicate. As part of a broader campaign of forced assimilation, Native American children had for decades been pushed into boarding schools that forbade—and punished—them for speaking their home languages. Now, on the field of battle, those same languages were saving lives.

One of the so-called “Five Civilized Tribes” of the southeastern United States, the Choctaw traditionally farmed corn, beans and pumpkins while also hunting, fishing and gathering wild edibles. Despite allying themselves with the United States in the War of 1812, they were pressured afterward into ceding millions of acres of land to the government.

Following the passage of the Indian Removal Act in 1830, most members of the nation were then forced to relocate to present-day Oklahoma in a series of journeys that left an estimated 2,500 dead. In what would become a catchphrase for all Indian removal west of the Mississippi River, a Choctaw chief described it as a “trail of tears and death.”

When the United States entered World War I in April 1917, it had not yet granted citizenship to all Native Americans, and government-run boarding schools were still largely attempting to stamp out their languages and cultures. Nonetheless, several thousand Native Americans enlisted in the armed forces to fight the Central Powers. Nearly 1,000 of them representing some 26 tribes joined the 36th Division alone, which consisted of men from Texas and Oklahoma.

“They saw that they were needed to protect home and country,” said Judy Allen, senior executive officer of tribal relations for the Choctaw Nation of Oklahoma, “so they went to the nearest facility where they could sign up and were shipped out.”

In the summer of 1918, the 36th Division arrived in France to participate in the upcoming Meuse-Argonne campaign, a major offensive along the Western Front. At that point, the outcome of the conflict was still in doubt.

“World War I really wasn’t decided until very, very late,” explained William C. Meadows, a Native American studies professor at Missouri State University and expert on code talking. “It wasn’t like World War II, where we clearly had them on the run.”

One main problem for the Allies was the Germans’ ability to listen in on their communications and to break their codes, which were generally based on either European languages or mathematical progressions. “We couldn’t keep anything secret,” Allen said.

An apocryphal story spread around that a German once interrupted a U.S. Signal Corps member sending a message to taunt his use of code words. Sending out human runners proved equally ineffective since about one in four were captured or killed. And other methods of communication, such as color-coded rockets, electronic buzzers and carrier pigeons, were too limiting, too slow, too unreliable or a combination thereof.

Soon after the Meuse-Argonne campaign got underway, a company commander in the 36th Division reportedly happened to overhear three of his soldiers—Solomon Lewis, James Edwards and Ben Carterby, who had attended the same Native boarding school together—conversing in Choctaw. In a flash, he recognized the military potential of the language, essentially unknown to the Germans, and persuaded his superiors to post a Choctaw speaker at various field company headquarters.

On October 26, 1918, the Choctaws were put to use for the first time as part of the withdrawal of two companies from the front. Having completed this mission without mishap, they then played a major role the following two days in an attack on a strongly fortified German position called Forest Ferme.

“The enemy’s complete surprise is evidence that he could not decipher the messages,” Colonel A.W. Bloor later wrote in an official report. The tide of battle turned within 24 hours, according to Bloor, and within 72 hours the Allies were on full attack.

At least 19 Choctaws subsequently completed a short training session. Lacking the words for certain modern-day military terms, they used “big gun” for artillery, “little gun shoot fast” for machine gun, “stone” for grenade and “scalps” for casualties, among other substitutions, thereby becoming true code talkers rather than simply communications operators speaking a little-known language.

“They create these code words, but they don’t actually get to use them because the war ends on the 11th [of November],” Meadows said. Even so, Colonel Bloor described the results of the training session as “very gratifying.” “It is believed, had the regiment gone back into the line, fine results would have been obtained,” he declared. “We were confident the possibilities of the telephone had been obtained without its hazards.”

A captured German later admitted that his side couldn’t make heads or tails of the Choctaw speakers, whom Allen credited with likely bringing about an earlier end to the war and saving hundreds of thousands of lives. The irony would not have been lost on them, she added, that “the same government that was asking them to use their native language to win the war was punishing people for speaking it back home.”

American Indians from at least five other nations also used their native tongues to transmit messages during World War I in an effort to confuse the Germans, although unlike the Choctaws they are not known to have invented intentionally coded vocabulary.

Indigenous coders made an even bigger impact during World War II when the U.S. government specifically recruited Comanche, Hopi, Meskwaki, Chippewa-Oneida and Navajo tribal members for such work. The Navajo developed the most complex code, with over 600 terms, for use in the Pacific Theater, compared with about 250 terms for the World War II-era Comanche and under 20 terms for the World War I-era Choctaw. Their work was crucial for victories at D-Day and Iwo Jima, among other important battles.

One of their codes translated Navajo terms into English letters that were then used to spell out words. For example, according to the National World War II Museum, the Navajo word for “ant,” "wo-la-chee," was used to represent the letter “a” in English. Another code contained word-to-word translations, but some had to be improvised. Since the Navajo had no word for "submarine," the code talkers agreed to use "besh-lo," which translates to "iron fish."

“Even the other tribe members back home didn’t know what this coded vocabulary meant,” Meadows said. “It was all gibberish to them.” In addition to the handful of intentionally coded Native American languages employed by the Allies, they used two dozen or so others on a more ad hoc basis. The opposition is not believed to have deciphered a single code talker message in either world war.

Only the Navajo, with more code talkers than all other Indigenous nations combined, have become relatively well known, in part due to the Hollywood film “Windtalkers.” They received congressional recognition for their exploits in 2000, whereas the remaining tribes had to wait eight more years until a bill passed praising them for their “dedication and valor.”

“Honoring Native American code talkers is long overdue,” the bill admitted. Pursuant to the legislation, a medal ceremony took place in November 2013 in Washington, D.C., with 33 tribes known to have had code-talking members in attendance. “My regret,” said Allen, “is that none of the code talkers were alive from our [Choctaw] nation to see this moment, and none of their children were alive.”