The Judicial Circuits Act of 1866 (ch. 210, ) reorganized the United States circuit courts and provided for the gradual elimination of several seats on the Supreme Court of the United States. It was signed into law on July 23, 1866, by President Andrew Johnson. It in effect denied him the opportunity of appointing any justices to the Supreme Court. It was the first major legislation dealing with the judiciary following the American Civil War. The Act redrew the boundaries of the judicial circuits and reduced the number of circuits from ten to nine. It also provided for the gradual reduction in the number of seats on the Supreme Court from the ten that had been authorized in 1863 to seven and established in large measure the geographical outlines of the circuits ever since. As it happened, only two seats, those of John Catron and James Moore Wayne, were abolished during the brief three-year interval of the Act's efficacy, before being superseded by the Judiciary Act of 1869. Thus, it never actually happened that the Court was reduced to seven in accordance with the language of the 1866 Act; rather, while it was in effect the Court comprised first nine and then eight justices. With the 1869 Act, Congress set the size of the Supreme Court at a total of nine justices once again. However, because Robert Cooper Grier created another vacancy in 1870 before a ninth justice could be appointed to the Court, the Court's de facto strength was actually reduced to the seven that had been stipulated by the 1866 Act, albeit shortly after that Act was no longer in force. Eventually, Grier was replaced by William Strong, and Joseph P. Bradley was installed in the lately created seat, restoring the Court to its new de jure strength of nine. The subsequent stability in circuit organization ended a period of frequent rearrangement of the states within the circuits. After establishing nine circuits in 1837, Congress in 1842 shifted several southern states in order to accommodate transportation routes used by the justices when traveling on circuit. In 1862 Congress incorporated six additional states into a restructured system of nine circuits, and within another year had abolished the California Circuit, placed California and Oregon in a Tenth Circuit, and reorganized the mid-western states. The 1866 Act ended a period in which the arrangement of the states into circuits was frequently