Madden v. Commonwealth of Kentucky, 309 U.S. 83 (1940):

"There is no occasion to attempt again an exposition of the views of this Court as to the proper limitations of the privileges and immunities clause. There is a very recent discussion in Hague v. Committee Industrial Organization. 13 The appellant purports to accept as sound the position stated as the view of all the justices concurring in the Hague decision. This position is that the privileges and immunities clause protects all citizens against abridgement by states of rights of national citizenship as distinct from the fundamental or [309 U.S. 83, 91]   natural rights inherent in state citizenship. 14 This Court declared in the Slaughter-House Cases15 that the Fourteenth Amendment as well as the Thirteenth and Fifteenth were adopted to protect the negroes in their freedom. This almost contemporaneous interpretation extended the benefits of the privileges and immunities clause to other rights which are inherent in national citizenship but denied it to those which spring from [309 U.S. 83, 92] state citizenship. 16 In applying this constitutional principle this Court has determined that the right to operate an independent slaughter-house,17 to sell wine on terms of equality with grape growers18 and to operate businesses free of state regulation19 were not privileges and immunities protected by the Fourteenth Amendment. And a state inheritance tax statute which limited exemptions to charitable corporations within the state was held not to infringe any right protected by the privileges and immunities clause. 20 The Court has consistently refused to list completely the rights which are covered by the clause, though it has pointed out the type of rights protected. 21 We think it quite clear that the right to carry out an incident to a trade, business or calling22 such as the deposit [309 U.S. 83, 93] of money in banks is not a privilege of national citizenship." 

[Madden v. Common wealth of Kentucky, 309 U.S. 83 (1940)]