How many justices are there on the Supreme Court?

The Supreme Court of the United States is composed of nine justices. This structure has been in place since the Judiciary Act of 1869, which established the number of justices at nine. These justices include one Chief Justice and eight Associate Justices, all appointed by the President and confirmed by the Senate.

This size allows for a diverse range of viewpoints while ensuring that the Court can reach decisions through majority votes. Each justice serves a lifetime appointment, which helps maintain the independence of the judiciary from the other branches of government. The reasoning behind having nine justices also minimizes the potential for tie votes, which would complicate the Court's ability to render definitive interpretations of law.

Other options such as seven, eleven, or thirteen do not align with the established structure of the Supreme Court, reflecting variations that have occurred in different historical contexts or in other judicial systems, but are not current to the U.S. Supreme Court.