Beginning in the 1870's corporate lawyers began asserting that corporations were persons with many of the rights of natural persons. It should be understood that the term "artificial person" was already in long use, with no mistake that corporations were claiming to have the rights of natural persons. "Artificial person" was used because there were certain resemblances, in law, between a natural person and corporations. Both could be parties in a lawsuit; both could be taxed; both could be constrained by law. In fact the corporations had been called artificial persons by courts in England as early as the 16th century because lawyers for the corporations had asserted they could not be convicted under the English laws of the time because the laws were worded "No person shall..."
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.
Before the Supreme Court determined that corporations were persons and hence had constitutional rights female citizens had decided that the Fourteenth Amendment should be interpreted to give them the right to vote. In Minor v. Happersett the Supreme Court ruled that "women" were not persons for the purposes of the Fourteenth Amendment.
http://www.iiipublishing.com/afd/santaclara.html From Citizens United briefs
The level of perverse logic governing the interpretation of Constitution is just mind boggling