US President, George W Bush, has pledged to move promptly to appoint a successor to US Chief Justice William Rehnquist.
Mr Rehnquist died at home in Arlington, Virginia, after a battle with thyroid cancer.
He was appointed to the Supreme Court by President Richard Nixon in 1971. During his career, he presided over President Bill Clinton's historic impeachment trial in 1999.
In 2000, Rehnquist joined the court's conservative majority as a bitterly divided Supreme Court ruled that ballot recounts in Florida should be stopped, effectively giving the presidency to George Bush.
The death of the 80-year-old conservative gives Mr Bush two openings to fill on the Supreme Court.
He has already nominated appeals court judge John Roberts to fill a vacancy created by the retirement of Justice Sandra Day O'Connor. Mr Roberts' Senate confirmation hearings were due to begin on Tuesday.
Mr Bush said he will choose in a 'timely manner' a highly qualified nominee to succeed Chief Justice Rehnquist.
