After winning a close race in Mississippi, Democrat Scott Colom will become the state's first black US senator for more than 150 years, and the third in history.
It is a historic result in the deeply conservative southern state that last sent a Democrat to the US Senate in 1982, and had not seated a black senator since 1875.
Colom follows Hiram Revels, who became the first black person ever to serve in the chamber when he was seated from 1870 to 1871, and Blanche Bruce, whose term ran from 1875 to 1881.
Revels was chosen as Mississippi's first senator after the Civil War, serving for just over a year and campaigning strongly for racial equality.
A few years later, Bruce, who was born into slavery, became the first black person to serve a full term in the US Senate. He remained in Washington after leaving the chamber and held a role in the Treasury.
Both terms came before the repressive Jim Crow laws began to enforce racial segregation across Mississippi and other southern US states.
A significant factor in Colom's victory was his success in mobilising young people and the state's large black population, who are expected to have turned out in high numbers.
In a victory speech, Colom referenced how Revels, who was a minister and served as a chaplain during the Civil War, gained support for his Senate campaign through his words.
"That's an example of the power of prayer, and through our history, there are so many people that lifted this state up through the power of prayer in very dark times," Colom said.
Prior to the result being called, the BBC spoke to students at Jackson State University, a historically black college in Mississippi. Many of them had voted for the first time and backed Colom.
"I really feel like a change is what we need," 18-year-old Jamyria Dunn said.
"I've had some amazing days in my life," she continued, "but seeing Mississippi, this state in particular, turn blue, would really bring a light to my heart that people just would not understand."
