*Rapper Nas makes history on Tuesday’s episode of “Finding Your Roots.”

“We introduced Nas to five generations – we’ve never been able to do this before for any African American – five generations of his enslaved ancestors,” host Henry Louis Gates told the TCA in July. “And we showed him an extremely rare document, something we’d never seen before, an actual 1859 bill of sale for his 3rd great grandmother whose name was Pocahontas Little.”

Also on the episode, President Obama’s senior advisor Valerie Jarrett learns of her legendary great-grandfather – MIT’s first African-American graduate and an accomplished architect – recruited to help build the prestigious Tuskegee Institute; and Angela Bassett traces her ancestors from slavery through emancipation…

Of all the stories on Tuesday’s episode, it was Nas’ ancestor’s bill of sale that had the most impact on Gates.

“Seeing Nas’s 3rd great grandmother’s actual bill of sale. You know, it was eerie,” Gates explained. “It moved me to tear up to think of a human being. It’s one thing to say our ancestors were all slaves, but to see the bill of sale where two people are bargaining for someone who happens to be your blood ancestor, that’s heavy.”

Below, Nas explains his on-camera reaction to seeing his ancestor’s bill of sale, and whether or not the experience of doing the show will inspire a future song:

“Finding Your Roots” with Nas, Angela Bassett and Valerie Jarrett premieres Tuesday (Oct. 28) at 8 p.m. on PBS.

Watch a promo of Tuesday’s episode “We Come From People”