President Trump's Supreme Court justice nominee, 49-year-old Judge Neil Gorsuch, beings his confirmation hearings Monday.
If confirmed, he would replace another conservative, Justice Antonin Scalia, who passed away in his sleep at age 79 in February 2016.
Since then, the court has had only eight justices.
(President Obama nominated Judge Merrick Garland to the bench in March, but Senate Republicans made good on their promise to block any pick until after the next president was elected. After Trump took office, Garland began hearing cases again as chief judge of the U.S. Court of Appeals for the District of Columbia Circuit.)
Read more about the current justices' history and their pathways to the nation's highest court:
Chief Justice John G. Roberts, Jr.
Roberts, 62, was appointed to the court in 2005 by President George W. Bush, who nominated him as chief justice. He took his seat Sept. 29, 2005, after a 78-22 vote in the Senate approving his nomination to become the 17th chief justice. Roberts graduated from Harvard College in 1976 and received his law degree from Harvard three years later. He served on the D.C. Circuit Court of Appeals before being appointed to the Supreme Court. Roberts was born in Buffalo, New York, and has two children with his wife, Jane Marie Sullivan.
Anthony M. Kennedy
Kennedy, 80, was nominated by President Ronald Reagan in 1987. He was confirmed in a 97-0 vote, and joined the bench Feb. 18, 1988, after the failed nomination of Robert Bork. Kennedy received degrees from Stanford University, the London School of Economics and Harvard Law School. After serving in private practice, Kennedy was a professor of constitutional law at the McGeorge School of Law, University of the Pacific. He was a member of the California Army National Guard in 1961. Kennedy was on the Ninth Circuit Court of Appeals when he was nominated. He is married to Mary Davis and has three children. Kennedy was born in Sacramento, California.
Thomas, 68, was nominated by President Bush in 1991. He was confirmed by the Senate in a 52-48 vote after partisan and contentious hearings, in which Anita Hill, a former aide to Thomas, testified to allegations of sexual harassment. Thomas denied the allegations in the highly publicized confirmation hearings and maintains his innocence. He joined the court on Oct. 23, 1991. Thomas graduated from Holy Cross College in 1971 and received his law degree from Yale Law School. He served as a judge on the D.C. Circuit Court of Appeals from 1990 to 1991. Prior to his judgeship, he was the assistant secretary for civil rights at the U.S. Department of Education and chairman of the U.S. Equal Employment Opportunity Commission. Thomas was born in the Pinpoint community near Savannah, Georgia. He married Virginia Lamp on May 30, 1987 and has one child by a previous marriage.
Ruth Bader Ginsburg
Ginsburg, 83, was nominated by President Bill Clinton to the Supreme Court in 1993 while serving as a judge on the D.C. Circuit Court of Appeals. She was confirmed in a 96-3 vote and joined the court on Aug. 10, 1993. She was a professor at Rutgers University School of Law from 1963 to 1972 and then at Columbia Law School from 1972 to 1980. Prior to her judgeship, Ginsburg worked as the ACLU’s General Counsel, where she launched the Women’s Rights Project. She received her undergraduate degree from Cornell University. She then attended Harvard Law School, but received her degree from Columbia Law School. Ginsburg was born in Brooklyn, New York. She married Martin D. Ginsburg in 1954, and has two children.
Stephen G. Breyer
Breyer, 78, was nominated to the court by President Bill Clinton in 1994. The Senate confirmed him in a 87-9 vote and he took the bench on Aug. 3, 1994. Breyer previously served for 10 years as a judge on the U.S. Court of Appeals for the First Circuit and for four years as its chief judge. He attended Stanford University and Magdalen College, Oxford, and received his law degree from Harvard Law School. He clerked for Supreme Court Justice Arthur Goldberg in 1964. Breyer was an assistant special prosecutor of the Watergate Special Prosecution Force, a special assistant to the assistant U.S. Attorney General for antitrust, as well as chief counsel for the U.S. Senate Judiciary Committee. He has three children with his wife Joanna Hare. Breyer was born in San Francisco, California.
Samuel Anthony Alito, Jr.
Alito, Jr., 66, was nominated by President George W. Bush in 2005. He took his seat on Jan. 31, 2006 after the Senate confirmed his nomination in a 58-42 vote, which followed Bush's withdrawal of his nomination of White House Counsel Harriet Miers. Alito previously served as assistant to the Solicitor General at the Department of Justice; deputy assistant Attorney General; and U.S. Attorney for the District of New Jersey. He was appointed to the U.S. Court of Appeals for the Third Circuit in 1990. Alito received his bachelor’s degree from Princeton University and his law degree from Yale Law School, where he was the editor of the Yale Law Journal. He is married to Martha-Ann and has two children. Alito was born in Trenton, New Jersey.
Sotomayor, 62, was nominated to the Supreme Court by President Barack Obama in 2009. She joined the court on Aug. 8, 2009, after the Senate voted 68-31 in support of her nomination. In 1991, President George H.W. Bush nominated her to the U.S. District Court, Southern District of New York, and she served in that role from 1992–1998. She was then nominated by President Bill Clinton to the Second Circuit Court of Appeals, where she served for 11 years. Sotomayor received her bachelor’s degree from Princeton University and her law degree from Yale Law School, where she served as an editor of the Yale Law Journal. She was born in Bronx, New York.
Kagan, 56, was appointed as Solicitor General of the United States by President Barack Obama in 2009. A year later, the President nominated her to the Supreme Court. She took her seat on Aug. 7, 2010, after a 63-37 vote in the Senate. Kagan clerked for Supreme Court Justice Thurgood Marshall in 1987. She was a law professor first at the University of Chicago Law School and later at Harvard Law School after briefly practicing law in Washington, D.C. She served for four years in the Clinton administration, as associate counsel to the President and then as deputy assistant to the President for domestic policy. She was also the dean of Harvard Law School from 2003 to 2009. Kagan was born in New York on April 28, 1960.
ABC News' Erin Dooley and Margaret Chadbourn contributed to this story.