I can hardly believe that any person can be found who will not admit that every one of these provisions is just. They are all asserted, in some form or other, in our Declaration or organic law. But the Constitution limits only the action of Congress, and is not a limitation on the States. This amendment supplies that defect, and allows Congress to correct the unjust legislation of the States, so far that the law which operates upon one man shall operate equally upon all. Whatever law punishes a white man for a crime shall punish the black man precisely in the same way and to the same degree. Whatever law protects the white man shall afford equal protection to the black man. Whatever means of redress is afforded to one shall be afforded to all. Whatever law allows the white man to testify in court shall allow the man of color to do the same. These are great advantages over their present codes.

James A. Garfield (1831-1881) US President (1881), lawyer, lay preacher, educator
Speech, House of Representatives (4 Apr 1871)
    (Source)

On the proposed 14th Amendment to the US Constitution, which forbade to each state the ability to "deny to any person within its jurisdiction the equal protection of the laws."