The United States made history as Ketanji Brown Jackson was sworn in as the first black woman to serve on the Supreme Court.

The 51-year-old's appointment by President Joe Biden means that white men are not in the majority on the nation's highest court for the first time in 233 years.

While her confirmation is a milestone, it will not change the 6-3 conservative majority on the court, which has come under fire for recent rulings broadening the right to bear arms, eviscerating abortion rights and limiting the government's power to curb greenhouse gases.

Justice Jackson's "historic swearing represents a profound step forward for our nation, for all the young, black girls who now see themselves reflected on our highest court, and for all of us as Americans," Mr Biden said in a statement.

"The Supreme Court just gained a colleague with a world-class intellect, the dignified temperament the American people expect of a justice, and the strongest credentials imaginable," he said.

"Amid this court's cruel assault on Americans' health, freedom and security, she will be a much needed force for equal justice for all," Nancy Pelosi, the top Democrat in Congress, said in a statement.

Justice Jackson spoke only to say her oaths during yesterday's brief ceremony.

She had picked up support from three Senate Republicans during a grueling and at times brutal confirmation process, delivering Mr Biden a bipartisan 53-47 approval for his first Supreme Court nominee.

He swearing-in marks a major moment for Mr Biden, who chaired the Senate Judiciary Committee in the 1980s and 1990s, meaning he has the unprecedented distinction of both naming and overseeing the appointment of a Supreme Court justice.

The appointment presents an opportunity for his administration to pivot from a spate of bad news in recent months, with Mr Biden's poll ratings still languishing below 40% amid runaway inflation ahead of midterm elections in November.

Crucially, it has allowed Mr Biden to show the black voters who rescued his floundering 2020 primary campaign that he can deliver for them.

At 42 days from nomination to confirmation, the process was among the shortest in history, although longer than it took to seat Donald Trump's last court pick during his presidency, Amy Coney Barrett.

Mr Biden also thanked the justice who Justice Jackson replaced, Steven Breyer, for his years on the court.

"Justice Breyer's integrity and his commitment to ensuring our nation's laws worked for the people have made him beloved by his colleagues and deeply respected across our country. I thank him again for his many years of exemplary service," Mr Biden said in the statement released by the White House.

As the final word on all civil and criminal legal disputes, as well as guardian and interpreter of the Constitution, the Supreme Court seeks to ensure equal justice under the law.

Four of the justices on the nine-member court are now women, making it the most diverse bench in history - although they all attended the elite law schools of Harvard or Yale.