Democratic candidate Scott Colom has won the U.S. Senate race in Mississippi, a conservative stronghold long held by Republicans, becoming the first Black person to hold the position since 1874.

Senator Blanche Bruce, a Black man born into slavery, was elected in 1874 and served until 1881. The state has remained a conservative stronghold for a century and a half, until Mr Colom’s victory.

“They did not believe a moment like this was possible, but I kept the faith,” Mr Colom said.

Mr Colom, 43, scored 49.2 per cent of the votes to defeat incumbent Senator Cindy Hyde-Smith, who conceded her loss on Wednesday.

“While this was not the outcome we worked for or hoped for, I respect the decision of Mississippi voters,” wrote Ms Hyde-Smith, who has been a senator since 2018.

The results add to the gains Democrats have so far recorded against Republicans.

Democrats now outnumber Republicans in the Senate, with 55-44 lawmakers, as Alaska remains undecided.

The Mississippi victory gives the Democrats a 55-44 advantage in the 100-member Senate, with the winner in one Senate race from last week’s election, in Alaska, yet to be determined.

Mr Colom, a district attorney, capitalised on voters’ frustration to oust Ms Hyde-Smith after she asked them “to pick another protein” in response to complaints that beef had become expensive.

The Democrat turned Ms Hyde-Smith’s response into an advert.

“Pick another protein? I’d rather pick another senator instead,” the ad said.

Mr Colom’s win adds to the mounting losses Republicans have conceded under President Donald Trump’s leadership.