In late July, the College Board, the administrators of the SAT and Advanced Placement exams, issued new guidelines for teaching AP United States history.

One change was to add a section on “American exceptionalism,” a concept as old as the country itself that the US is qualitatively different — and, arguably, better — than other nations.

While “exceptionalism”, at its best, nurtures civic pride, at its worst, it blinds Americans to the country’s long history of remarkably unexceptional ideas and actions. What George Santayana so neatly encapsulated over a century ago remains painfully true: “Those who cannot remember the past are condemned to repeat it.”

As a historian and tour guide, I often see this collective American blind spot on display as I lead walks of historic New York City. On Central Park’s Bethesda Terrace, a quaint carving of a witch on a broomstick is a jumping off point for discussing the deep anti-Irish sentiment in the city following the influx of immigrants after the 1845 potato famine.

Political cartoonists like Thomas Nast depicted the Irish as apes and Catholic bishops as monsters; “No Irish Need Apply” signs appeared in shop windows. As I tell these stories, I can see the anger grow in some of my listeners. One woman flat-out told me to stop talking. “You can’t say that,” she admonished. “It’s not true.”

I clarified that these were not my opinions, but those of many Protestant New Yorkers a century and a half ago. “No,” she repeated.

She did not want to know about an America where such things were possible — which, of course, meant she didn’t want to confront the idea that she might still live in such a place.

‘America’s porous borders’

Similarly, in Chinatown one day, my explanation of the 1882 Chinese Exclusion Act, which effectively banned Chinese immigration for six decades, led one visitor to launch into a tirade about America’s porous borders. I shook my head — not at his critique, which had some valid points — but at his inability to connect the country’s history with his own past. You see, he was Chinese American.

The Chinese Exclusion Act had been an affront to his heritage; current immigrants were an affront to his political and economic ideals. He saw no link between the two.

In revising their standards, the College Board is hoping to bridge this gap between the nation’s history and students’ contemporary experiences by providing “sufficient time to immerse students in the major ideas, events, people and documents of US history,” where before “they were instead required to race through topics.”

The revisions were also a reaction to conservative input on the AP curricula revision process — beginning in 2012, there had been a groundswell of conservative criticism against the proposed standards, which the Republican National Committee argued “emphasise[d] negative aspects of our nation’s history while omitting or minimising positive aspects”.

The College Board sought input from teachers, historians and parents to shape teaching guidelines that present a “clearer and more balanced approach to the teaching of American history.”

Unfortunately, the new standards have also softened the language about the country’s most shameful episode: its 244-year history of slavery. As recent “heritage not hate” rallies centred on the Confederate battle flag illustrate, there is perhaps no greater myth in America today than the idea that the Civil War was predominantly about states’ rights. Well, it was about one right: the right to own Africans as chattel.

In Texas, new textbooks minimise the role of slavery in the Civil War, despite the fact that the state’s own ‘Declaration of the Causes which Impel the State of Texas to Secede from the Federal Union’ explicitly stated that the Confederacy was “established exclusively by the white race, for themselves and their posterity” and that “the servitude of the African race, as existing in these States, is mutually beneficial to both bond and free ...”

Gone from the state’s new books are mentions of Jim Crow or the Ku Klux Klan. It’s the “you can’t say that” woman in Central Park writ large. This is especially troubling since Texas’s large population means that its curricular standards influence textbook buying in other states.

America is, in fact, an exceptional place. Founded by groups as diverse as indigenous Native Americans, Dutch merchants, English separatists, Spanish missionaries, French frontiersman and Africans — both free and enslaved — the country’s diversity stretches back four centuries. Each of these groups, and the many immigrants who followed them, brought strengths, and weaknesses, with them.

We are right to celebrate the strengths, but if we don’t shine a light on the weaknesses, we are ignoring at least half the story.

— Guardian News & Media Ltd

James Nevius is author of multiple books about New York City history, most recently Footprints in New York: Tracing the Lives of Four Centuries of New Yorkers.