This commentary is from George Longenecker of Middlesex, a retired writer and teacher.

There has been a lot of talk in recent months about what the history of the United States should teach. I thought of some of the fury – which is nothing new – and what is actually taught in most classrooms. I have taught American history several times during my career.

Maybe the critics are right. I was critical. However, criticism and criticism are at the heart of education – and democracy. To criticize is to look at both sides of a problem.

The history of the United States is full of contradictions, the dualities of our history. Duality means having different or opposing parts. Two seemingly opposite things can be true at the same time. We have seen it throughout the history of our nation.

Critical breed theory is an often-used bogeyman or dog whistle, but that’s not what is taught in public schools or college courses. It specifically examines the legal system and how it has not always advanced civil rights.

What some people are trying to restrict is a history program that looks openly and critically at the United States, including its history of civil rights.

The United States of America is founded on a Constitution that provides strong protections for civil liberties and a process of change through amendment. It has been a model for other constitutions.

However, in the original Constitution, slavery was sanctioned, with the clause of three fifths and the clause of the fugitive slave.

Slavery was a huge business, both in the North and in the South. Slaves were worth $ 3 billion, about $ 91 billion in today’s dollars. To say that slavery was good or that it was not the cause of civil war is misleading. Perhaps a few slaves were treated decently, but for the most part slavery was grueling hell ending in untimely death.

The South was a beautiful place, and still is, yet it was built on the backs of 4 million people who had no more rights than horses and were treated worse than most dogs.

Reconstruction and the 13^e The amendment ended slavery in 1865. The South was destroyed economically. Millions of former slaves were alone. However, without land or education, the former slaves were desperately poor. Reconstruction began to help the former slaves as well as the poor whites, and the South had black elected officials because anyone could vote.

Jim Crow’s laws and lynchings put an end to the Reconstruction. As immigration to the United States increased, its own rights as black citizens were taken over.

Immigration to the United States has given many people new lives and new opportunities. Many more people have immigrated to the United States than they have emigrated. My grandparents were immigrants, like many of our ancestors. Although sometimes nostalgic, my grandparents were happy to live here.

However, the United States had made room for new settlers by driving their native people off their lands and exterminating them. On the other side of the family, my great-grandparents lived in Kansas on a free homestead farm. This farm allowed them to put several children to university. Yet the contradiction in US history is that the prosperity of immigrant families and their descendants was gained at the expense of Kiowa and other Native Americans.

The treatment of refugees and immigrants by the United States has been contradictory. Some groups have been welcomed. Others were used for cheap labor. Some have been harassed, such as Haitian refugees trampled by border patrol officers on horseback last month.

The United States has provided work, but at a cost. The 19^e and 20^e centuries have been marked by strikes in steel mills, coal mines and railroads. It was grueling jobs that brought America into the industrial age.

This country has provided housing for its citizens and immigrants. Yet, due to systemic discrimination in real estate sales and financing, the net worth of black Americans is much lower than that of others. It is a legacy of discrimination that dates back to slavery.

I reminded my students that healthcare has improved dramatically over the past century. If it was the beginning of the 20^e century, I would probably have died at the age of 60, many of them would not have reached adolescence, and many women would die in childbirth. Thanks to modern preventive health care, better nutrition and vaccines, we are living longer. Yet in Mississippi, the infant mortality rate for blacks is double that of whites, the same as in Albania. Disparities in health care make us much less healthy as a nation than Canada or the UK.

The United States is a beautiful country, from Acadia of Maine to the Channel Islands of California. Yet the industrial age has arrived with environmental degradation, including climate change with its storms and fires.

We are a nation of dualities, of contradictions. As a nation, we are an enigma. We are a nation of disparities. Asking teachers to never criticize our problems will not make us a better nation. Only by teaching history critically can we understand ourselves.