(The Declaration of Independence printed with the names of the signers. Printer Mary Katharine Goodard’s name is at the bottom. (Library of Congress, Rare Book and Special Collections Division, Continental Congress & Constitutional Convention Broadsides Collection))

I’m sure you’ve seen her. She’s everywhere — on museum walls and in stacks of books. She’s in galleries, paintings, libraries, manuscripts, photographs and cemeteries.

“Unknown Woman.”

Because for centuries, that’s mostly what women rated in the compiling of human history.

“She was quite the social butterfly, she was everywhere,” said Joan Wages, president of the nascent National Women’s History Museum. Wages’s mission in life is to replace Unknown Woman with the names, faces and stories that changed our world.

Unknown Woman was especially popular in early America, when historians largely ignored the dynamic lives of women who helped build the nation.

Historians’ priorities were usually “the kind of history that ‘mattered’ at the time: the history of big national events, influential men and their families,” Carolyn Eastman, a history professor at Virginia Commonwealth University, said in an email interview.

The collection, study and preservation of manuscripts “displayed the same sense of priorities: war, great men, family dynasties. So some women’s history got collected along the way if they were connected to big families, but that history wasn’t undertaken on a purposeful level the way that other histories were prioritized,” she said.

I ran smack into this earlier this month, when I wrote about the woman whose name is printed at the bottom of the Declaration of Independence: Mary Katharine Goddard. Or, Mary Katherine Goddard. Depends where you look.

Problem is, there are few places to look.

She was the printer in Baltimore who churned out copies of America’s founding document once it was signed by the Founding Fathers. In a risky move, she added a line outing herself as the printer:

“Baltimore, in Maryland: Printed by Mary Katharine Goddard.”

For years beforehand, she’d been the publisher of the Baltimore newspaper her brother had abandoned, the Maryland Journal, running fiery editorials about the revolution, running scoops from the battlefront of Bunker Hill. But she did it all as “M.K. Goddard.”

Despite the spelling of her own name on the Declaration of Independence, every other reference to her has her middle name spelled “Katherine.” In the National Archives, the Library of Congress, the Maryland Hall of Fame, even the display about her in the Smithsonian has that “e.”

I could find one letter she wrote, to President George Washington, asking for her job back after she was removed because the new postmaster general believed that women weren’t up for the travel the job required. She signed that letter “Mary K. Goddard.”

But this isn’t only about the pesky and common misspellings from ye olden days.

The same thing happened to the heroic rider who turned a decisive battle during the American Revolution by riding through the night to alert the troops that the British were coming.

No, not Paul Revere. His ride and the way he spelled his name was well documented because he became a journalist after the war and regaled (and regaled) the story.

Sybil Ludington was 16 when in 1777 she rode twice as long as Revere had, from New York to Connecticut, to alert the militia that British troops were about to attack a supply depot. Gen. Washington personally thanked her for the ride — it was a huge deal at the time. But she didn’t regale; she quietly went back to her life, and men of her time tossed her story aside. Her headstone in New York reads “Sibbell.”

Surely, Katharines and Sybils everywhere can relate. But what this really shows us is that so many of the documents that must have existed surrounding these women were treated as disposable.

Same with photos. Wages said they are constantly trying to identify the “Unknown Woman” in historical photographs. And we’re not just talking the days of daguerreotypes. The women who helped send Americans into space were only identified in most NASA photos as “the computers” as they stood beside the men who were each identified by name.

Like the women in that photo, a good chunk of American history is missing, said Wages, whose museum still doesn’t have a home. It relies on a robust website but has been fighting for a permanent space in the nation’s capital for two decades.

The disputed image of Mary K. Goddard on the cover of the 1783 Baltimore Almanack. (John Carter Brown Library at Brown University)

Goddard, who ran the busy and crucial Baltimore post office as well as a bookstore, print shop and newspaper at the time that Congress was meeting just down the street from her office, never got a portrait when she became postmaster. Her offices were raided, and her life was threatened. But she persisted, keeping her shop going as a combination of Gmail, The Washington Post, Snapchat, Facebook and Instagram during the birth of our nation. (It’s now a Rite Aid. And the plaque commemorating her shop has the “Katherine” spelling.)

“Only in the last 10-15 years have historians come to recognize her role as a printer and postmistress (and her role with the printed copy of the Declaration),” Eastman said. “In other cases, women printers were dismissed as having only taken those jobs because a husband or brother died/ left, as if that mitigates their importance as media figures and businesswomen.”

The only likeness of this remarkable woman we could find may not even be her, it turns out.

The John Carter Brown Library at Brown University identifies an etching on the cover of Goddard’s 1783 “Baltimore Almanack” as Goddard. But I heard from readers who disputed that. The same image on a pendant is catalogued by the Walters Art Museum in Baltimore as the actress Ann Brunton.

There’s a chance Goddard simply kept a copy of that likeness in her Baltimore Almanack, which was like a diary, because she was a fan of the popular actress, as many were at the time.

But this is also the picture that the Smithsonian displays of Goddard.

Historians have known for years that much of our history is squishy like this.

“In 1922, Arthur Schlesinger, Sr., criticized his fellow historians for tacitly assuming that ‘one-half of our population have been negligible factors in our country’s history,’ ” wrote Eva Moseley, an archivist who curated the Schlesingers’ collection in the 1970s.

“Neglect of women has not only meant little or no space given to them in historical writings, but it has also meant little or no space given to women’s papers in manuscript repositories and little or no effort to acquire these materials,” Moseley wrote. “Women themselves have often considered their papers trivia and treated them accordingly. Many papers have been lost forever, while others exist only as spotty or scattered bits and pieces.”

Which leaves us with “Unknown Woman.”

And frankly, we’re sort of done with her.

Twitter: @petulad