The Judiciary Act of 1789, ch. 20, 1 Stat. 73 created the office of the Chief Justice and five associate justices, but the role of the Chief Justice was not described in the act.
Various scholars have written extensively about the role of the Chief Justice over the years and have identified five principal roles of the Chief Justice:
The Chief Justice presides over Supreme Court proceedings as well as presidential impeachment trials (U.S. Const. art. 1, § 3, cl.6). Other duties and responsibilities include admitting lawyers to the Supreme Court Bar, enforcing standards of courtroom dress and decorum, controlling the flow of judicial proceedings, serving as Circuit Justice for the busy District of Columbia, Fourth, and Federal Circuits (each Associate Justice is assigned to a circuit court), chairing Court conferences on case selection and on argued cases, and assigning the drafting of Court opinions.
The office of the Chief Justice differs from that of an Associate Justice only in the administrative duties, such as being the ceremonial leader where protocol dictates; assigning colleagues as Circuit Justices during recesses (28 U.S.C § 42); assigning a consenting retired predecessor or retiring Associate Justice to perform judicial duties in any circuit (28 U.S.C § 294); signing a certificate of disability for an Associate Justice of the Supreme Court who desires to retire for disability (28 U.S.C § 372(a)).
The Chief Justice plays the role of the court defender, safeguarding the U.S. Supreme Court as an institution, by, for example, controlling the Justices' workload and protecting the status and political independence of the Court.
In 1888, the title of the Chief Justice was changed from "Chief Justice of the Supreme Court of the United States" to "Chief Justice of the United States." See William A. Richardson, Chief Justice of the United States or Chief Justice of the Supreme Court of the United States?, 49 New Eng. Hist. Soc'y Reg. 275, 278 (1895), (implying the importance of the office of Chief Justice not just of the Supreme Court, but of the United States federal judiciary).
The Chief Justice is the chair of the Judicial Conference of the United States. The Conference was created in 1922 at the urging of Chief Justice Taft, and it makes policy and rules with regard to the administration of the United States courts. As the chair, the Chief Justice presides over the Conference and controls the agenda, and he appoints the chairman of over twenty committees.
He is also the Chair of the Board of the Federal Judicial Center. The primary function of the Center is to engage in research, training, and education for the judicial branch. In addition, much of the responsibility of appointing the director of the Administrative Office of the United States Courts and overseeing the Administrative Office's work falls on the Chief Justice.
In 1970, Chief Justice Burger started a tradition of publishing an annual report on the federal judiciary. The report is available in the following publications:
Some of the functions that the Chief Justice is called upon to perform include administering the oath of office at the inauguration of the President and of governors and secretaries of the several territories and leading important presidential commissions.