In Jackson, Biden delivers on a campaign promise to make the historic appointment and to further diversify a court that was made up entirely of white men for almost two centuries. He has chosen an attorney who would be the high court’s first former public defender, though she also possesses the elite legal background of other justices.

Jackson would be the current court’s second Black justice — Justice Clarence Thomas, a conservative, is the other — and just the third in history.

The news was confirmed by a person familiar with the matter who spoke on the condition of anonymity to discuss it before the president’s official announcement later Friday.

She would also be only the sixth woman to serve on the court, and her confirmation would mean that for the first time four women would sit together on the nine-member court.

The current court includes three women, one of whom is the court’s first Latina, Justice Sonia Sotomayor.

Jackson would join the liberal minority of a conservative-dominated court that is weighing cutbacks to abortion rights and will be considering ending affirmative action in college admissions and restricting voting rights efforts to increase minority representation.

Biden is filling the seat that will be vacated by Justice Stephen Breyer, 83, who is retiring at the end of the term this summer.

Jackson, 51, once worked as one of Breyer’s law clerks early in her legal career. She attended Harvard as an undergraduate and for law school, and served on the U.S. Sentencing Commission, the agency that develops federal sentencing policy, before becoming a federal judge in 2013.

Her nomination is subject to confirmation by the Senate, where Democrats hold the majority by a razor-thin 50-50 margin with Vice President Kamala Harris as the tie-breaker. Party leaders have promised swift but deliberate consideration of the president’s nominee.

The next justice will replace one of the more liberal justices, so she would not tip the balance of the court, which now leans 6-3 in favor of conservatives.