Time magazine has published an article by jailed former soldier Chelsea Manning in which she pays tribute to civil rights leaders Martin Luther King Jr, Malcolm X, and gay rights campaigner Harvey Milk.

Ahead of Thursday’s Thanksgiving Day in America, Time magazine asked a number of prominent public figures, including First Lady Michelle Obama, to share what they’re grateful for.

Chelsea wrote: I’m usually hesitant to celebrate Thanksgiving Day. After all, the Puritans of the Massachusetts Bay Colony systematically terrorized and slaughtered the very same Pequot tribe that assisted the first English refugees to arrive at Plymouth Rock. So, perhaps ironically, I’m thankful that I know that, and I’m also thankful that there are people who seek out, and usually find, such truths.

“I’m thankful for people who, even surrounded by millions of Americans eating turkey during regularly scheduled commercial breaks in the Green Bay and Detroit football game; who, despite having been taught, often as early as five and six years old, that the ‘helpful natives’ selflessly assisted the ‘poor helpless Pilgrims’ and lived happily ever after, dare to ask probing, even dangerous, questions.

“Such people are often nameless and humble, yet no less courageous. Whether carpenters of welders; retail clerks or bank managers; artists or lawyers, they dare to ask tough questions, and seek out the truth, even when the answers they find might not be easy to live with.”

In her article Manning then turns her attention to those who have fought and achieved social justice and equality but have paid the ultimate price. Among them was gay rights activist Harvey Milk, the first openly gay male politician in America who fought for gay rights ordinances but was shot dead by a former colleague in 1978.

She wrote: “I’m also grateful for having social and human justice pioneers who lead through action, and by example, as opposed to directing or commanding other people to take action. Often, the achievements of such people transcend political, cultural, and generational boundaries. Unfortunately, such remarkable people often risk their reputations, their livelihood, and, all too often, even their lives.”

Manning added: “For instance, the man commonly known as Malcolm X began to openly embrace the idea, after an awakening during his travels to the Middle East and Africa, of an international and unifying effort to achieve equality, and was murdered after a tough, yearlong defection from the Nation of Islam. Martin Luther King Jr., after choosing to embrace the struggles of striking sanitation workers in Memphis over lobbying in Washington, DC, was murdered by an escaped convict seeking fame and respect from white Southerners.

“Harvey Milk, the first openly gay politician in the US, was murdered by a jealous former colleague. These are only examples; I wouldn’t dare to make a claim that they represent an exhaustive list of remarkable pioneers of social justice and equality—certainly many if not the vast majority are unsung and, sadly, forgotten.”

Chelsea Manning is at Fort Leavenworth in Kansas and serving 35 years for leaking classified material to the website WikiLeaks. She was sentenced in August.

Fort Leavenworth is refusing to provide Manning with gender confirmation treatment.

Earlier this month, Manning said she would take the US Army to court over its continued refusal to provide her with access to gender confirmation therapy.