While there were many outstanding lines from Michelle Obama's speech at the Democratic National Convention, one line in particular stood out.

"I wake up every morning, in a house that was built by slaves," the first lady told the audience.

GIF from the 2016 Democratic National Convention.

The statement was a powerful reminder that our country's very foundation rests on exploited labor and racial injustice, and it was a testament to our progress as a nation and the historic nature of her husband's own presidency. It was a powerful moment.

It's a line she's used before. For example, here's an excerpt from her commencement speech this June at City College of New York:

"Graduates, it’s the story that I witness every single day when I wake up in a house that was built by slaves, and I watch my daughters — two beautiful, black young women —head off to school — (applause) — waving goodbye to their father, the President of the United States, the son of a man from Kenya who came here to American — to America for the same reasons as many of you: To get an education and improve his prospects in life."

Not everyone was happy about her statement, however, and perhaps the most notable dissent came from Bill O'Reilly of Fox News.

During the July 26 edition of "The O'Reilly Factor," the pundit tried to make a few clarifications to Michelle Obama's words.

On his show, O'Reilly said he believes it's important to note that the White House was not built solely using slave labor (though Mrs. Obama never claimed that to be the case — what she did say, however, is true). Additionally, he implied that the use of slave labor was OK because "slaves that worked there were well-fed and had decent lodgings provided by the government."

Photo by Dimitrios Kambouris/Getty Images for Hollywood Reporter.

Broadway legend Audra McDonald took to Twitter to give O'Reilly a history lesson on what those "decent lodgings" looked like.

Warning: Tweets include graphic imagery.

What message should we take from all this? It's pretty simple: There are countless things we can argue as being "liberal" versus "conservative," but maybe the question of "Was slavery really all that bad?" doesn't need to be one of them.

It's 2016. It's OK to look back at history and admit there were certain things the country's founders did that were morally reprehensible — slavery being one of them.

That line in Michelle Obama’s speech was about progress and the need to acknowledge — and not erase or excuse — the painful parts of history that force us to grow as a country. To bring up the past and remind ourselves that the White House was built using slave labor is not divisive. It’s what helps us build a better future.