Charles Ventura

USA TODAY

Michelle Obama delivered a powerful speech during the Democratic National Convention on Monday, as the first lady shed light on the historical significance of her family's eight years at the White House as its first African-American family.

"I wake up every morning in a house that was built by slaves," Mrs. Obama said in her keynote address. "I watch my daughters — two beautiful, intelligent, black young women — playing with their dogs on the White House lawn."

As it turned out, one person was not entirely amused and went so far as to "fact check" the first lady's comments.

FOX News personality and political lightning rod Bill O'Reilly defended the working conditions slaves faced while building the White House by offering the following explanation during The O'Reilly Factor on Tuesday:

"Slaves that worked there were well-fed and had decent lodgings provided by the government, which stopped hiring slave labor in 1802. However, the feds did not forbid subcontractors from using slave labor. So, Michelle Obama is essentially correct in citing slaves as builders of the White House, but there were others working as well. Got it all? There will be a quiz."

Twitter, naturally, sounded off in a blaze of fury:

O'Reilly later opened his show Wednesday, defending his assessment and blasting various media groups on how they portrayed his analysis.

"It is a given that slavery is an abomination," O'Reilly said onThe O'Reilly Factor. "But reporting the story behind Mrs. Obama's very valid points does not diminish the horror of enslavement as these dishonest critics allege."