who determines the number of justices on supreme court
Supreme Court of the United States Article III of the United States Constitution does not specify the number of justices. The Judiciary Act of 1789 called for the appointment of six "judges". Although an 1801 act would have reduced the size of the court to five members upon its next vacancy, an 1802 act promptly negated the 1801 act, legally restoring the court's size to six members before any such vacancy occurred. As the nation's boundaries grew, Congress added justices to correspond with the growing number of judicial circuits: seven in 1807, nine in 1837, and ten in 1863.[69]
Supreme Court of the United States According to federal statute, the Court normally consists of the Chief Justice of the United States and eight associate justices who are nominated by the President and confirmed by the Senate. Once appointed, justices have lifetime tenure unless they resign, retire, or are removed after impeachment (though no justice has ever been removed).[2] In modern discourse, the justices are often categorized as having conservative, moderate, or liberal philosophies of law and of judicial interpretation. Each justice has one vote, and it is worth noting while a far greater number of cases in recent history have been decided unanimously, decisions in cases of the highest profile have come down to just one single vote, thereby exposing the justices' ideological beliefs that track with those philosophical or political categories. The Court meets in the Supreme Court Building in Washington, D.C.