What was meant by the Fourteenth Amendment's Privileges or Immunities Clause?1 Did it incorporate the U.S. Bill of Rights against the states or did it do something else? In retrospect, the Clause has seemed to have the poignancy of a path not taken-a trail abandoned in the Slaughter- House Cases and later lamented by academics, litigants, and even some judges.2 Although wistful thoughts about the Privileges or Immunities Clause may seem to lend legitimacy to incorporation, the Clause actually led in another direction. Long-forgotten evidence clearly shows that the Clause was an attempt to resolve a national dispute about the Comity Clause rights of free blacks.3 In this context, the phrase "the privileges or immunities of citizens of the United States" was a label for Comity Clause rights, and the Fourteenth Amendment used this phrase to make clear that free blacks were entitled to such rights.
The incorporation thesis runs into problems already on the face of the Privileges or Immunities Clause. The Bill of Rights guarantees rights generally, without distinguishing citizens from other persons. In contrast, the Fourteenth Amendment sharply juxtaposes the privileges or immunities of "citizens" with the due process and equal protection rights owed to "any person." It therefore is not easy to understand how the Amendment's guarantee of the privileges or immunities of citizens can be understood to refer to the rights of persons protected by the Bill of Rights.4
What then was the Privileges or Immunities Clause doing when it guaranteed that "[n]o State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States"? The answer lies in the nineteenth-century dispute about whether free blacks had the benefit of the Comity Clause. This clause assured that "[t]he Citizens of each State shall be entitled to all Privileges and Immunities of Citizens in the several States."5 Many states, however, especially in the South, denied Comity Clause rights to free blacks-the justification being that only citizens of the United States were entitled to the benefit of the Comity Clause and that free blacks were not U.S. citizens. Opponents of slavery responded in kind, arguing that free blacks were U.S. citizens and so were entitled to the privileges and immunities secured by the Comity Clause. Thus, each side interpreted this clause to exclude or include free blacks on the basis of whether or not they were federal citizens. In these circumstances, opponents of slavery defended the Comity Clause rights of free blacks in terms of "the privileges and immunities of citizens of the United States." After the Civil War, the Fourteenth Amendment echoed this antislavery interpretation of the Comity Clause and secured it in the Constitution.6
The phrase employed by the Fourteenth Amendment's Privileges or Immunities Clause thus has a history-indeed, a genealogy-that clearly reveals its historical meaning. It will be seen that allusions to privileges and immunities could occur in different contexts with different meanings.7 But only one combination of context, text, and meaning led directly to the Fourteenth Amendment, thereby revealing a historical genealogy that leaves the meaning of the Privileges or Immunities Clause unmistakable. Although this history has been largely forgotten, it was once a central element in the struggle against slavery and a foundation of the Fourteenth Amendment. And it had nothing to do with incorporation.
1. The Missing Evidence.-The incorporation thesis has seemed plausible because scholars have tended to focus either on too narrow a slice of evidence (which excludes what is essential) or on too broad a range of evidence (which conflates different contexts). In fact, although the relevant evidence comes from a wide array of sources, it arose in a specific context, in which "the privileges and immunities of citizens of the United States" had a very specific meaning. …