Fiery debate has erupted at the first congressional hearing in a decade to explore whether the descendants of US slaves should be compensated.
Some witnesses said reparations would damage the relationship between white and black Americans, while others said it was imperative to achieve justice.
Several Democratic White House hopefuls have taken up the idea of reparations.
But Republican leader Mitch McConnell has made it clear no reparations bill will pass while he controls the Senate.
The House of Representatives judiciary subcommittee on the constitution, civil rights and civil liberties said Wednesday's hearing would examine "the legacy of the Trans-Atlantic Slave Trade, its continuing impact on the community and the path to restorative justice".
Lawmakers considered a bill proposed by Texas Democrat Sheila Jackson-Lee to set up a commission to study the question of reparations for slavery.
Hundreds of people lined up outside the hearing venue and filled the overflow room to watch.
What are the arguments against reparations?
Republican witness Coleman Hughes, an African-American writer and New York student, argued during the hearing that such restitution "would insult many black Americans by putting a price on the suffering of their ancestors".
"If we were to pay reparations today, we would only divide the country further, making it harder to build the political coalitions required to solve the problems facing black people today."
The second Republican witness, African-American former NFL player Burgess Owens, also rejected the idea, saying: "What strangers did to other strangers 200 years ago has nothing to do with us because that has nothing to do with our DNA."
Congressman Mike Johnson, a Louisiana Republican, was booed as he spoke against "the injustice of monetary reparations from current taxpayers for the sins of a small subset of Americans from many generations ago".
The hearing was held on Juneteenth, which commemorates 19 June 1865 when Texas slaves finally learned they were free, two-and-a-half years after President Abraham Lincoln's Emancipation Proclamation.
What was the case in favour?
Actor Danny Glover told the panel that reparations would cure "the damages inflicted by enslavement and forced racial exclusionary policies".
"A national reparations policy is a moral, democratic and economic imperative," Mr Glover said.
Economist Julianne Malveaux emphasised that she wanted lawmakers to address structural inequalities affecting black Americans.
"When zipcode [postal code] determines what kind of school that you go to, when zipcode determines what kind of food you eat - these are the vestiges of enslavement that a lot of people don't want to deal with."
Lawmakers also heard from writer Ta-Nehisi Coates, whose 15,000-word cover story for the Atlantic magazine in 2014, The Case for Reparations, reignited the whole debate.
He said: "Enslavement reigned for 250 years on these shores. When it ended, this country could have extended its hollow principles of life, liberty and pursuit of happiness to all. But America had other things in mind."
A conundrum for Democrats
Back in June 2014, Atlantic magazine author Ta-Nehisi Coates made what has been widely considered the most comprehensive case for reparations for black Americans. In his piece, he argued that compensation was due not just for the historic injustice of slavery, but for the discrimination and depredation, official and unwritten, the community had been subjected to in the time after emancipation.
The consequences, in housing, employment and education policies, are felt even to this day.
His arguments resonate with many on the left, who believe the US as a nation has a responsibility to right these wrongs. There has been an ongoing debate, within the Democratic presidential field and now the halls of Congress, over the way forward.
It is also a debate that is likely to fall on deaf ears for much of the country, who view the horrors of slavery as the stuff of history books. It's an issue that is easy for political opponents to dismiss, stoking the fires of racial resentment that have smouldered in America during the Trump era.
This presents a conundrum for Democratic policymakers that is more than familiar by now. Should they try to do what many in their party believe is right - or follow the least resistant path to political success?
Would reparations pass Congress?
The issue - which has been debated since the US Civil War - has bubbled up in the race for next year's presidential election.
Democratic candidates such as Cory Booker, Kamala Harris, Beto O'Rourke and Bernie Sanders have said that as president they would form a commission to study the matter.
But the most powerful congressional Republican has made clear the idea does not have his support.
Asked about the issue on Tuesday, Mr McConnell told reporters: "We've tried to deal with our original sin of slavery by fighting a civil war, by passing landmark civil rights legislation," he added.
"We elected an African-American president.
"I think we're always a work in progress in this country, but no-one currently alive was responsible for that."