"It's basically genocide," Williams says. "The Muslims from the north come down and raid villages in the south. The men are killed or used as carriers and the women and children are brought back to the north as slaves."

In the border area where Williams would be traveling, militia raids are frequent, and Western rescue planes could be targets of northern weapons.

Williams knew he could have been risking his life traveling to Sudan, but he says he still felt it was something that he had to do.

A religion concentrator who plans to be a doctor someday, Williams says he believes his Christian faith compels him to help others.

"Me going on the trip didn't end slavery, the mission would have gone on without me," he says. "But it was something I had to see with my own eyes so I could tell the story. I felt a calling from God, and that's why I had to do it."

His parents opposed the trip at first. Eventually, his mother decided that God would protect her son. His father only gave his blessing days before Williams left.

Williams and the seven other members of his team arrived in Sudan on Sept. 5. They visited five different sites in Bahr El Ghazal, a province in the northern region of South Sudan.

In this border area between the north and south, some dissident Muslims have formed a peace agreement with the Dinka people.