President Trump’s chief of staff John Kelly on Monday night praised Confederate Gen. Robert E. Lee and said that “both sides” in the Civil War fought in good faith.

Kelly was speaking during an interview on Fox News when he made the comments, defending the historical significance of the Confederacy.

“Robert E. Lee was an honorable man. He was a man who gave up his country to fight for his state,” Kelly told the network about the Southern general in the bloody war between the North and the South.

The Civil War was fought after the South seceded from the Union mostly due to a disagreement over slavery.

“The lack of the ability to comprise led to the Civil War,” Kelly said.

“Men and women of good faith on both sides made their stand where their conscience had them make their stand.”

Chelsea Clinton blasted Kelly’s version of history in a tweet Monday night.

“General Kelly, there is no ‘compromise’ regarding slavery. Ever,” Clinton tweeted. “And, the Constitution’s original 3/5ths Compromise was an abomination.”

Clinton was referring to a 1787 agreement reached between Northern and Southern states that, for purposes of determining representation in Congress, counted each free person in the South as one person — and each slave as three-fifths of a person.

More then 600,000 Americans are estimated to have died in the Civil War.