Kevin Gover first objected to the name of Washington’s professional football team in 1973 in a letter to then-owner Edward Bennett Williams.

Williams never acknowledged the letter, Gover recalled recently, admitting that his high-schooler’s passion may have been a bit over the top. “I probably wouldn’t have answered that letter if I’d received it, either,” he said with a rueful smile.

Gover, a citizen of the Pawnee Nation and director of the Smithsonian Institution’s National Museum of the American Indian, has since polished his diplomatic skills. But he well remembers the shock he felt moving here from Oklahoma with his family and suddenly encountering the name seemingly everywhere he turned.

“The nastiest thing people ever said to us had become the name of an NFL team? I didn’t comprehend it then, and I don’t now,” Gover said during a visit to The Post last week.

Gover is now in a position to do something about it: not to persuade the imperturbable Dan Snyder, of course, but to help other Americans understand the historical context that makes the name so offensive. And for those of us who think we get that a slur is a slur, who think we know the narrative of white expropriation from Native Americans, Gover wants to show that the history is richer and more complex than we may have been taught.

A key fact: In the early decades of the 20th century, when teams across the country were adopting Indian names and mascots, there were virtually no Native Americans left — just 250,000 in 1900. The extermination was almost complete.

“There were so few that the imaginary Indians became much more real than real Indians,” Gover said.

Just as whites fashioned a falsely benign history of slavery, so the textbooks portrayed a mythical version of settler-native relations. Whereas the true history was one of treaty relationships forged and then broken, and mass killings through the introduction of European diseases, Americans came to believe they had obtained their land by means of valiant conquest.

Custer’s defeat at Little Bighorn became central to the narrative because it portrayed the Indian as a “formidable adversary,” Gover said, which “made it so much more heroic to inflict defeat on them.”

The Indian population has rebounded to 2.5 million tribal citizens and another 1.5 million who identify themselves as Native American without belonging to a tribe, Gover said. But for many Americans, the “imaginary Indian” still remains more real.

“The textbooks seem uninterested in reviewing and revising what they say about Indians,” he said. “Teachers still teach about Pocahontas, Little Bighorn, the Trail of Tears — at best an incomplete story, and at worst incorrect.”

Now celebrating its 10th anniversary, the Indian museum on the Mall is offering one corrective in an exhibit that opened Sunday: “Nation to Nation: Treaties Between the United States and American Indian Nations.” Unlike past exhibits, for which the museum allowed tribes to decide which objects to exhibit, this is a fully curated, scholarly exposition, and the Smithsonian will produce classroom materials to accompany it. “We know that teachers want to get it right,” Gover said.

The exhibit shows how treaties initially were respectful documents between Indian nations, on the one hand, and vulnerable colonies and states on the other, each with something to gain through diplomacy; how they evolved as the United States strengthened and committed itself to the decimation of the tribes; and how, in the latter half of the 20th century, the treaties provided a rallying point and a legal buttress for Indians seeking to reestablish themselves.

“As we’ve had a return to nation-to­nation relationships, Indian country has begun to prosper again,” Gover said.

Prosperity is relative, of course, and many Indian communities have a long way to go. As do white perceptions, Gover noted.

“People come into the museum and ask, ‘Where are the real Indians?’ — because I’m wearing a coat and tie,” said Gover, a Princeton grad, lawyer and former assistant secretary of the interior. For many, the only “real Indians” are on reservations, whereas “easily two-thirds of us” live in cities, he said.

Which brings us back to that football team.

“One of the things that’s strange is to have Mr. Snyder lecture us on what should be important to American Indians, after a couple of carefully screened visits to reservations,” Gover said. “Those of us who’ve made a career of this can only roll our eyes, I suppose.”

But what of the owner’s contention that a majority of Indians support the name?

“I don’t know who those Indians are,” Gover said. “I really don’t.”

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