We want to understand the Privileges or Immunities Clause: “No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States.” These words originally expressed their meaning in the context of fi ve conceptually-or textually-similar types of provisions:

• the Comity Clause of Article IV Section 2 Clause 1, • treaty-based promises of the rights of American citizenship, • the power under Article I Section 8 Clause 4 to create new citizens of

the United States, • the grants of judicial power regarding citizens in Article III Section 2

Clause 1, and • state-constitutional bans on special privileges or immunities for par-

ticular citizens.