Al Capone. Whitey Bulger. The list of Alcatraz prisoners reads like a litany of gangsters and hardened criminals. But in the 19th century, the infamous island was also home to 19 prisoners rarely found in maximum security cells: Hopi men.

Their crime? Rebelling against plans to send their children to “assimilation” boarding schools hundreds of miles away from their reservations. But in 1894, their parents resisted—and paid the price.

At the time, the Hopi people and the United States government were locked in a decades-long land conflict. As one of the oldest documented cultures, the Hopis have lived in what is now northeastern Arizona for thousands of years, farming in the inhospitable land of the Four Corners region and living in the oldest continuously inhabited village in North America, Oraibi.

In the 16th century, Spanish soldiers invaded the area and white settlement began. The Hopi people made treaties with the Spaniards and, later, the Mexicans. At the end of the Mexican-American War, in 1848, theTreaty of Guadalupe Hidalgo recognized indigenous pueblo dwellers, including the Hopi, and their land rights. But in the 1870s, the United States defied the treaty, claiming Hopi land as public land and designating an agent to oversee the Americanization of the Hopi people.

At the time, U.S. policy was to establish reservations and send Native American children to “Indian schools”—boarding schools where their languages were forbidden, their traditional ceremonies were not recognized and their behavior was policed in an attempt to make them comply with the culture and social customs of white Americans. Students were given new names, taught that Native Americans were inferior to white people and kept away from their parents in an attempt to assimilate the younger generation.

In 1887, the first government-run school for Hopi children opened. It was 40 miles or more from most villages and many parents refused to send their children there and to the other schools opened by the government. At the same time, the Hopi resisted government plans to divide traditionally communal lands into individually owned tracts in an attempt to break up tribal groups.

In the eyes of the government, there were “friendlies”—Hopi who complied—and “hostiles” who did not. The Indian agent attempted to force the hostiles to comply, raiding their houses and withholding critical resources.

“They do not want to follow the Washington path,” wrote Constant Williams, the government-appointed agent, of the resisting Hopi. “They do not want their children to go to school; that they do not want to wear the white man’s clothes; that they do not want to eat the white man’s food…they do want the white man to let them alone.”

In the eyes of the government, that could not be tolerated. In late 1894, Williams arrested 19 of the hostiles. They were taken first to Fort Defiance in Arizona, then to Alcatraz Island in California—approximately 1,000 miles away.

At the time, Alcatraz was a military prison. (It became a federal penitentiary in 1934.) Conditions there were primitive and harsh, with poor sanitation and ventilation and considerable fire risk. For the government, and the white public, this was seen as what the Hopi men deserved for their defiance. Local papers wrote about the men in articles filled with racial slurs, decrying them as “crafty redskins” and painting them as murderers.

“They have not hardship aside from the fact that they have been rudely snatched from the bosom of their families,” wrote the San Francisco Call in February 1895. “[They] are prisoners and prisoners they shall stay until they have learned to appreciate the advantage of education.”

But though the press depicted the men’s days as leisurely and their conditions as hotel-like, the reality was anything but. The men were forced into tiny cells and made to spend their days sawing logs. They suffered in an environment far removed from their families and the plains. Two of the incarcerated men’s wives gave birth to children who died while they were imprisoned, and rumors circulated that some of the men had been killed or died while in prison. (It remains unclear how many Hopis died at Alcatraz.)

After a year of imprisonment, the men were released and returned to the Hopi reservation in Arizona. Later, the men said they had been promised their children would not have to go to school. However, that promise was not kept. For years, the government continued forcing the Hopi people to send their children to school and pushing them to divide their land into individual plots.

Though government attempts to force assimilation continued, so did Hopi resistance. Today, few remember the Hopi men who faced harsh imprisonment rather than give their children up to the forces of assimilation and colonialism. But there is an ongoing attempt by the National Park Service, which now oversees the island, and the Hopi community to commemorate their struggles and document their time at Alcatraz.