Was the 14th Amendment about corporations? One of the 1886 judges, Samuel F. Miller, had not thought so in 1872, only six years after the Amendment had become law, when the court was "called upon for the first time to give construction to these articles." In the Slaughterhouse Cases (83 U.S. 36 (1872)), Miller delivered the majority opinion and discussed the Thirteenth Amendment and the Fifteenth Amendment as well as the Fourteenth as follows:

The most cursory glance at these articles discloses a unity of purpose, when taken in connection with the history of the times, which cannot fail to have an important bearing on any question of doubt concerning their true meaning. Nor can such doubts, when any reasonably exist, be safely and rationally solved without a reference to that history, for in it is found the occasion and the necessity for recurring again to the great source of power in this country, the people of the States, for additional guarantees of human rights, additional powers to the Federal government; additional restraints upon those of the States. Fortunately, that history is fresh within the memory of us all, and its leading features, as they bear upon the matter before us, free from doubt.

...

We repeat, then, in the light of this recapitulation of events, almost too recent to be called history, but which are familiar to us all, and on the most casual examination of the language of these amendments, no one can fail to be impressed with the one pervading purpose found in them all, lying at the foundation of each, and without which none of them would have been even suggested; we mean the freedom of the slave race, the security and firm establishment of that freedom, and the protection of the newly made freeman and citizen from the oppressions of those who had formerly exercised unlimited dominion over him.

(Graham, Howard Jay, Everyman's Constitution, State Historical Society of Wisconsin, 1968. See also Graham, Howard Jay, "The Conspiracy Theory of the Fourteenth Amendment," The Yale Law Journal, Vol. 47: 341, 1938)

It has been argued that the men who wrote the 14th Amendment specifically meant for the word person to be a loophole which you could drive a giant corporation through. Apparently in one of the railroad cases an attorney who had been on the committee that drafted the amendment waved a paper before the court claiming that it documented such; but the paper was not entered as evidence, nor apparently was it shown to anyone, nor was it saved. However, careful research has shown that, John A. Bingham the member of Congress who is known to have been chiefly responsible for the phraseology of Section One when it was drafted by the Joint Committee in 1866, had, during the previous decade and as early as 1856-1859, employed not one but all three of the same clauses and concepts he later used in Section One. More important still, Bingham employed these guarantees specifically and in a context which suggested that free Negroes and mulattoes rather than corporations and business enterprise unquestionably were the persons' to which he then referred.

Later, in Northwestern Nat Life Ins. Co. v. Riggs (203 U.S. 243 (1906)), having accepted that corporations are a type of people, the court still ruled that the 14th Amendment was not a bar to many state laws that effectively limited a corporation's right to contract business as it pleases.

Two Supreme Court judges, Hugo Black and William O. Douglas, later rendered opinions attacking the doctrine of corporate personhood. Quoted here is the conclusion of Justice Black's opinion:

If the people of this nation wish to deprive the states of their sovereign rights to determine what is a fair and just tax upon corporations doing a purely local business within their own state boundaries, there is a way provided by the Constitution to accomplish this purpose. That way does not lie along the course of judicial amendment to that fundamental charter. An amendment having that purpose could be submitted by Congress as provided by the Constitution. I do not believe that the Fourteenth Amendment had that purpose, nor that the people believed it had that purpose, nor that it should be construed as having that purpose.

(Hugo Black, dissenting, Connecticut General Life Insurance Company v. Johnson (303 U.S. 77, 1938).)

Justice Black was not alone in his questioning of the legitimacy of corporate personhood. Justice Douglas, dissenting in Wheeling Steel Corp. v. Glander (337 U.S. 562, 1949), gave an opinion similar to, but shorter than, the one quoted above, to which Justice Black concurred.

http://en.wikipedia.org/wiki/Corporate_personhood