Section 9. Clause 1. The Migration or Importation of such Persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the Year one thousand eight hundred and eight, but a Tax or duty may be imposed on such Importation, not exceeding ten dollars for each Person. Powers Denied to Congress GENERAL PURPOSE OF THE SECTION This section of the Constitution (containing eight clauses restricting or prohibiting legislation affecting the importation of slaves, the suspension of the writ of _habeas corpus_, the enactment of bills of attainder or _ex post facto_ laws, the levying of taxes on exports, the granting of preference to ports of one State over another, the granting of titles of nobility, etc.,) is devoted to restraints upon the power of Congress and of the National Government,[1432] and in no respect affects the States in the regulation of their domestic affairs.[1433] The above clause, which sanctioned the importation of slaves by the States for twenty years after the adoption of the Constitution, when considered with the section requiring escaped slaves to be returned to their masters (art. IV, Sec. 1, cl. 3), was held by Chief Justice Taney in Scott _v._ Sanford,[1434] to show conclusively that such persons and their descendants were not embraced within the term "citizen" as used in the Constitution. Today is interesting only as an historical curiosity. Clause 2. The Privilege of the Writ of Habeas Corpus shall not be suspended, unless when in Cases of Rebellion or Invasion the public Safety may require it. HABEAS CORPUS Purpose of the Writ