No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

As we shall see, it was this Amendment which the Supreme Court ultimately used to extend the religion clauses of the First Amendment to the states. Surprisingly, it was not the "privileges and immunities" clause or even the "equal protection" clause that the Court fastened upon, but the "due process" clause. But that was much later. At the time, religion was not mentioned or thought of in connection with any of the Civil War Amendments.

Religion was not mentioned in the Civil War Amendments for the excellent reason that there was no religious issue in the Civil War. There was a religious issue afterward. President Grant was an adherent of the most complete separation between church and state. He was not satisfied that the Constitution kept the federal government out of the religious affairs of the people; he wanted the states to be subjected to a similar prohibition. In the last year of his administration, an amendment was introduced in the Congress to accomplish this purpose. Known for its proposer in the House, James G. Blaine, who eight years later would be Republican candidate for President, the Blaine Amendment would have extended the religious clauses of the First Amendment to the states and, for good measure, have added a prohibition of aid to parochial schools.

The House passed the Blaine Amendment and sent it to the Senate where it was proposed by Senator Frelinghuysen, former Attorney General of New Jersey and a leader of the Congress which had passed the Fourteenth Amendment. Senator Frelinghuysen noted that the First Amendment was "an inhibition on Congress, and not on the States." He continued:

The [Blaine Amendment] very properly extends the prohibition of the first amendment of the Constitution to the States. Thus the [Blaine Amendment] prohibits the States, for the first time, from the establishment of religion, from prohibiting its free exercise, and from making any religious test a qualification to office.

Senator Eaton of Connecticut found the Blaine Amendment offensive. "I am opposed," he said, "to any State prohibiting the free exercise of any religion; and I do not require the Senate or the Congress of the United States to assist me in taking care of the State of Connecticut in that regard." Senator Whyte agreed: "The first amendment to the Constitution prevents the establishment of religion by congressional enactment; it prohibits the interference of Congress with the free exercise thereof, and leaves the whole power for the propagation of it with the States exclusively; and so far as I am concerned I propose to leave it there also."

In other words, both proponents and opponents of the Blaine Amendment agreed that nothing in the Constitution prohibited the states from establishing a religion or from interfering with the free exercise thereof. Certainly no one imagined that the Fourteenth Amendment had extended the religion clauses of the First Amendment to the states. As many members of the Congress which considered the Blaine Amendment had sat in the Congress which voted for the Fourteenth Amendment seven years earlier, it is unlikely they overlooked its possible significance.

The Blaine Amendment did not receive the necessary votes in the Senate. For the next half century it was reintroduced in Congress after Congress. It never passed. It was not abandoned, however, until the Supreme Court, by judicial fiat, made it superfluous.