A 51-year-old federal appeals court judge is poised to become the first-ever black woman to sit on the United States Supreme Court.

President Biden is set to nominate Judge Ketanji Brown Jackson, who sits on the prestigious Court of Appeals in Washington, D.C. ... this according to ABC News.

Biden reportedly called Jackson to offer her the nom and she accepted during a call Thursday night.

Biden was true to his word when he said during the 2020 campaign he would nominate a Black woman.

Jackson was the frontrunner from the get-go, although there were 3 other jurists Biden was considering. Jackson is a Harvard Law School grad who clerked for the Justice she's in line to replace -- Stephen Breyer.

In her early career, Jackson was a federal public defender. She'd be the first, former federal public defender to serve on the High Court since Thurgood Marshall. This is significant -- most of the Justices have no practical experience in the criminal justice system ... at least no experience in the trenches.

As for her chances, well there's a razor-thin Democrat majority in the Senate, but confirmation is likely unless there are surprises. Jackson's already been confirmed by the Senate 3 times -- twice when she was elevated to 2 federal courts and a third time when she was confirmed to sit on the U.S. Sentencing Commission.

As for how Jackson could change the court ... not much for the immediate future. She's replacing a like-minded jurist in Breyer, so the balance of power is still 6-3 in favor of conservative justices.

And, fun fact ... while she was at Harvard she acted opposite Matt Damon in a drama class.