While teaching U.S. history at a public charter high school in the District, Julian Hipkins III noticed that students tended to assume that “race” was as old as mankind. “Almost like it was natural, a given,” as he put it.

So, using some specialized lessons, Hipkins helped the students explore the invention of race and the reasons for it, as laid out in colonial law. Especially the Virginia slave codes enacted between 1640 and 1705.

Question: How did wealthy landowners thwart the efforts of enslaved Africans and European indentured servants to join forces in a common struggle for economic justice?

Answer: Divide and conquer through the invention of race. Make the white servants feel superior to black slaves by virtue of skin color; manipulate poor whites into believing that any perceived gains by blacks had come at their expense.

“I started by having students get together in groups and think up laws that could be used to separate one group of people from another and laws that would make one group of people feel superior to another,” said Hipkins, who taught 11th-graders at the Capital City Public Charter School in Northwest Washington.

The students, reluctantly, brainstormed. And when Hipkins showed them how similar their concocted laws were to actual slave codes, some of the students recoiled in disbelief. “They said, ‘You made that up!’ ” Hipkins recalled. “I said, ‘No, those are actual laws.’ They said, ‘That’s crazy. Somebody actually sat down and wrote those?’ ”

Students eventually homed in on the essential question: Who stood to benefit from such diabolically inspired disunity among people whose economic interests were so intertwined?

“That led to a discussion about how oligarchs defend their interests,” Hipkins said. “We would come back to that throughout the school year because the students noticed how race was being used as a wedge issue again and again.”

Hipkins used a lesson called “The Color Line,” by Bill Bigelow, curriculum editor at Rethinking Schools magazine. The material can be downloaded from the Zinn Education Project.

The pattern of exploitation that the students discovered does not fit neatly into the standard high school history narrative of the noble birth of a nation. So it is often overlooked. But the process has been widely documented.

Thomas and Mary Edsall, for example, described it in their 1991 book, “Chain Reaction: The Impact of Race, Rights and Taxes on American Politics:”

“Just as race was used, between 1880 and 1964, by the planter-textile-banking elite of the South to rupture class solidarity at the bottom of the income ladder, and to maintain control of the region’s economic and political systems, race as a national issue over the past twenty-five years has broken the Democratic New Deal ‘bottom-up’ coalition — a coalition dependent on substantial support from all voters, white and black, at or below the median income.”

That fracturing of the Democratic coalition, the Edsalls argue, “permitted, in turn, those at the top of the ‘top down’ conservative coalition to encourage and to nurture, in the 1980s, what may well have been the most accelerated upward redistribution of income in the nation’s history — a redistribution fed by the tax, spending and regulatory policies of the Reagan and Bush administrations.”

That upward redistribution continues, and racism is still being used keep poor and working-class blacks and whites fighting over crumbs, while the top 1 percent takes the cake. Echoes can be seen in Donald Trump’s outreach to poor and working-class whites by castigating immigrants as those people who are taking their jobs.

But that does not have to be the end of the history lesson.

“When students learned how race had been created, how the structure of white supremacy had been constructed, they began to realize that it could also be destroyed,” said Hipkins, who recently left his teaching post to become a curriculum specialist for D.C.-based Teaching for Change.

For the past 400 years, every generation has produced heroic advocates for liberty and justice. With a more-enlightened view of the short but destructive history of race, the students now had a choice:

Join in a struggle to build an anti-racist America, or accept racism “as a given” and rejoin the masses in stultified maintenance of a futureless status quo.