“SoJo,” the cat of Representative Ayanna Pressley, Democrat of Massachusetts, is a celebrity in her own right. SoJo is a minor Twitter influencer; her appearance there wins likes and replies that include snapshots of admirers’ cats. Her popularity reflects how social media tastes lean toward cute pet clips and also speaks to me as a historian of black women’s politics. As Ms. Pressley explained, “SoJo” is short for Sojourner Truth Pressley Harris. Yes, Ms. Pressley’s pet carries the name of Sojourner Truth, one of early America’s best remembered African-American antislavery and women’s rights activists.

Truth knew that names tell a story, and so she changed hers. She was born enslaved in the 1790s, and, after her freedom in 1827, she changed her name from Isabella Van Wagenen, baptizing herself anew as Sojourner Truth. This started a life spent wandering in search of truths both religious and secular. Since then, black women have made sure that she is not forgotten, naming their clubs and schools for this foremother. They have sent her into the cosmos. In 1995, 13-year-old Valerie Ambroise, a student in Bridgeport, Conn., won the honor of naming NASA’s Mars rover with Sojourner: “She was a heroine to blacks, slaves and women. She acted on her strong feelings about life and the way it should be.” She added: “It’s only logical that the Pathfinder be named Sojourner, because she is on a journey to find truths about Mars.”

Naming is one essence of freedom. Some enslaved people resisted subjugation when naming their children; some changed their names, hoping to elude greedy owners and brutal slave catchers. With emancipation, many more threw off the names given to them by slaveholders, acquiring for the first time last names such as Freeman that passed on how it felt to savor the first moments of liberty. Even today, some of us carry the names of the families who called our forebears property. Also among us are those who are called by “X” and by unique names, signs of how the quest for freedom persists.

Credit…National Portrait Gallery, Smithsonian Institution

For nearly two centuries, black women passed on names as remembrances of struggles for freedom, dignity and citizenship. We can find these stories in articles, textbooks, museum exhibits and even popular culture. But the lives of these sheroes are not being newly discovered in the 21st century. Instead, they are inherited from women who handed them down to inspire next generations. Passed along, from mothers to daughters to granddaughters, our names carry with them visions of freedom.

Ida. Maya. Rosa. Fannie Lou. Harriet. Sojourner. Passing down these black women’s names have become a tradition through which we keep their legacies alive and ourselves more free.

When Harriet Tubman gave up her birth name, Araminta Ross, it was a first step toward stealing herself from slavery. The law did not respect her marriage to John Tubman, as enslaved people had no claim to marital rights. Still she defiantly took his last name. Her first name she likely borrowed from her mother and a sister, both called Harriet. A new name was a rebirth that raised Tubman up from slavery’s social death, even before she escaped and then valiantly rescued enslaved people, scouted for the Union Army and eventually campaigned for women’s votes. And she made certain she was hard to forget. In 1903, Tubman donated the land for what became the Harriet Tubman Home for the Aged in upstate New York and passed the last years of her life in that very place.

Credit…Library of Congress

Black genius and black suffering inspired Mary Church Terrell, as she crisscrossed the country, standing before crowds to decry lynching and demand women’s suffrage. An activist and a mother, Terrell sometimes brought her young daughter on the road. Each time she introduced Phyllis, it was a lesson in black women’s history. Terrell had named her daughter for Phillis Wheatley, bringing the trials of an enslaved woman and poet of the 18th century into the politics of the 20th. In turn, black women did the same for Terrell, naming their political clubs for her, and that tradition persists. In 2018, her alma mater, Oberlin College, inaugurated the Mary Church Terrell Main Library during a ceremony that also installed the school’s first black female president, Carmen Twillie Ambar.

Naming continued to inspire into the civil rights era. Shirley Chisholm, the first black woman to sit in the U.S. House of Representatives, in 1968, and then first to vie for the presidency as a major party candidate in 1972, is best remembered for her slogan: “Unbought and Unbossed.” Chisholm was a student of politics and of history. At Brooklyn College, in the Harriet Tubman Society, Chisholm learned about “white oppression, black racial consciousness and black pride.” On the campaign trail, Tubman, along with Sojourner Truth, gave Chisholm resolve: “A lot of this hostility is because I’m a woman … I can understand when I read about Sojourner Truth and Harriet Tubman. And I say to myself, if those two little old black women had to go through what they did, well maybe I, too, better try to be strong.”

Credit…Collection of the Smithsonian National Museum of African American History and Culture, Gifted with pride from Ellen Brooks

Today, Stacey Abrams, the former minority leader of the Georgia House of Representatives, said much the same. She draws inspiration from the legacies of those who came before her, women with names that have echoed across time. Ms. Abrams credits her own grandmother, as well as women like Tubman; Chisholm; Ida B. Wells; and Barbara Jordan, the first black woman to represent a Southern state in Congress, as inspiring her to hold office and to champion the voting rights of all Americans in the 21st century.

My own name has won me a few fans, like my friend James, a 10-year-old who thought it was pretty cool that I share a name with a character from the “Doctor Who” television series: Martha Jones. Also Martha was my great-aunt, and a woman who helped raise my mother. But it was my father who was determined to name me for her. Aunt Martha, the child of German immigrants, had disowned my mother when she married my father, a black man from North Carolina. My name, Martha, is in this sense a small gesture of reconciliation and of hope for a world in which racism would not decide who could marry. The Supreme Court’s decision in Loving v. Virginia, which made my parents’ marriage legal in all 50 states, was still years ahead. My father hoped that in choosing my name, he might help get us there.