Ketanji Brown Jackson, the first Black woman to serve on the US Supreme Court, was sworn in on Friday in a ceremony in Washington that Vice President Kamala Harris and President Joe Biden both attended.
In the body that makes decisions on some of the most significant social and legal issues in the US, Jackson nominated to the highest court by Biden, will be a member of the progressive minority.
The conservative majority of six justices, three of whom were chosen by Biden's predecessor, Donald Trump, may leave the 52-year-old with few options.
In recent months, that majority has used its influence to increase gun rights and eliminate the constitutional right to an abortion.
Biden, a Democrat, appointed Jackson at the end of February after promising to choose the first African-American woman to the nation's highest court during his campaign.
She succeeded the 84-year-old Justice Stephen Breyer, who retired.
Although there was intense divisiveness around the court, her confirmation by the Senate occurred without a hitch, and her appointment did not alter the balance of power on the bench.
The Supreme Court's 2022–2023 term is set to start on Monday.