Real Housewives of Atlanta's Porsha Stewart Thought the Underground Railroad Was a Real Train: Watch Now

Reality star received a lesson from her castmembers during a recent trip to Savannah

Apparently, somebody wasn't paying attention in history class. Which made for a pretty embarrassing moment on reality TV.

On Sunday night's episode of the Real Housewives of Atlanta, the ladies took a trip to Savannah, where they embarked upon a Freedom Trail tour, visiting a landmark church that was used as part of the Underground Railroad during the pre-Civil War era.

The tour guide explained that the holes in the floor were used for ventilation as people would pass under the church in a small four foot area of crawl space, which confused the heck out of Stewart, who was under the impression that the Underground Railroad was in fact a real train.

No, seriously.

"Well there has to be an opening for the railroad at some point because somebody's driving the train," Porsha replied, genuinely perplexed. "It's not electric like what we have now," she added as the tour guide laughed.

"It wasn't a train, baby," Phaedra Parks explained as Stewart's costars stood in shock. "That was just a euphemism, baby."

"It wasn't a train at all," Parks continued as Kandi Burruss tried to help clear up Porsha's confusion.

"Just a railroad," Stewart said, still seemingly a bit baffled. "Oh, I'm thinking it was like widespread."

While Phaedra and Kandi simply tried to educate Porsha, the rest of the ladies had their own thoughts to share on Stewart's headline-making flub.

"Really, like really? You actually thought there was an actually train that took them through," Cynthia Bailey vented in her confessional before adding that "[Porsha's] grandfather, Hosea Williams, just rolled over in his grave."

Stewart's grandfather was a famous civil rights leader and a trusted member of Martin Luther King Jr.'s inner circle.

"It's almost hurtful to watch her be so dumb," Kenya Moore, Stewart's nemesis and former pageant queen said.

And of course NeNe Leakes gave her own sassy take, exclaiming,: "Ding dong! He's not talking about putting baby sis on the train or on the damn public bus."

While Stewart has yet to address her controversial comments, Kenya Moore wrote about last night's episode on her Bravo blog and didn't hold back while discussing her disapproval for Porsha's lack of education.

"Porsha is an embarrassment to her grandfather, his legacy, her family, and most importantly, herself," she wrote. "It's easy to laugh and call her dumb, but the reality is even more painful -- WE have failed her. Our educational system has failed her, anyone who coddled her or encouraged her to focus on her makeup, weave, and shoes to find a man to take care of her rather than her education has failed her. Anyone laughing at this gross ignorance has failed her. I encourage all people to teach our young girls to value the things that one cannot take away from you."

(E! and Bravo are both part of the NBCUniversal family.)