A senator for the state of Arkansas is defending comments he made on slavery in the United States.
Republican Senator Tom Cotton said US founders viewed slavery as a "necessary evil upon which the union was built".
His comments were criticised as an attempt justify the slavery of black people.
He is introducing legislation to ban federal funds for a project by the New York Times newspaper, aimed at revising the historical view of slavery.
The project's founder expressed outrage at the remarks.
What did Senator Cotton say?
Senator Cotton told the Arkansas Democrat-Gazette that he rejects the idea that the US was a systemically racist country to its core.
"We have to study the history of slavery and its role and impact on the development of our country because otherwise we can't understand our country.
"As the Founding Fathers said, it was the necessary evil upon which the union was built, but the union was built in a way, as [Abraham] Lincoln said, to put slavery on the course to its ultimate extinction."
Two hundred and thirty years after the government formed by the US Constitution went into effect and 154 years after slavery was officially abolished in the country, the legacy of the nation's founding and the role of the "peculiar institution", as it was often called, is still a subject of intense debate.
Tom Cotton this weekend managed to insert himself in the middle of the roiling controversy by saying that the nation's founders viewed slavery as a "necessary evil" and put it on a course to extinction - assertions that are both highly contentious.
While some early leaders viewed the continued existence of slavery as necessary, and others saw it as evil, there was little overlap between the two perspectives. And as for ending the practice, while the Constitution allowed the outlawing of the US slave trade in 1808, slavery was woven into the document - most notably in how slaves ("all other persons") were counted for congressional representation.
In the end, it took a war to dismantle the institution of slavery in the US. If the founders had indeed set the practice on a course to extinction, it turned out to be a bloody one whose lasting consequences remain to this day.
On Thursday Senator Cotton introduced the Saving American History Act, aimed at stopping funding for 1619, an initiative which bases US history teaching around the first arrivals of slave ships in the US in August of that year.
The project won the Pulitzer prize for commentary for its founder, New York Times journalist Nicole Hannah-Jones, but it has been criticised by many US conservatives as an attempt to shift focus from American independence to slavery.
After five prominent historians wrote to the Times to flag historical inaccuracies, the newspaper corrected the article with two words; the phrase "some of" was added to describe the number colonists who wanted to secede from Britain in order to preserve slavery.
"The entire premise of the New York Times' factually, historically flawed 1619 Project… is that America is at root, a systemically racist country to the core and irredeemable," Senator Cotton said, calling the project "left-wing propaganda".
"I reject that root and branch. America is a great and noble country founded on the proposition that all mankind is created equal. We have always struggled to live up to that promise, but no country has ever done more to achieve it."
Responding to Senator Cotton's legislation, Ms Hannah-Jones tweeted that if slavery was justified as a means to an end, anything else could be too.
If chattel slavery — heritable, generational, permanent, race-based slavery where it was legal to rape, torture, and sell human beings for profit — were a “necessary evil” as @TomCottonAR says, it’s hard to imagine what cannot be justified if it is a means to an end. https://t.co/yScNxPq6ds— Ida Bae Wells (@nhannahjones) July 26, 2020
Senator Cotton then responded, denying that he was justifying slavery and describing Hannah-Jones' comments as "lies".
"Describing the *views of the Founders* and how they put the evil institution on a path to extinction, a point frequently made by Lincoln, is not endorsing or justifying slavery," he tweeted after the backlash.
What is the background?
The row comes amid the rise of the Black Lives Matter movement. The death of George Floyd, an unarmed black man, in Minnesota in May sparked huge protests across the US against police brutality and racism.
Protesters and police in the city of Portland, Oregon, have clashed repeatedly in recent days. The confrontations have escalated since a deeply controversial decision by President Donald Trump to send federal law enforcement to the city. Under the US constitution, policing is a matter for individual states, not for the federal government.
Senator Cotton has been a strong critic of the nationwide protests, describing them in an opinion piece for the New York Times as an "orgy of violence" and backing Donald Trump's threat to use troops to quell unrest.
The article was widely criticised, and more than 800 Times employees signed a letter denouncing its publication, saying it contained misinformation.
The newspaper later apologised, saying the piece fell below its editorial standards. Opinion editor James Bennet resigned as a result.