• Most states in early America had established churches
• Established Church: a church officially supported (and paid for) by the government
• Dissenters from established churches were tolerated but not always treated equally
• First Amendment originally limited only federal government, not state governments
• First Amendment contains two clauses on religion: Establishment Clause and Free Exercise Clause

First, we need to remember that when the First Amendment was drafted, most of the newly independent states of the United States already had established churches. These churches were the "official" religion in their colonies and were paid for by taxes collected by the government. Dissenters, or members of churches that disagreed with the established church, were tolerated in every colony, but they had to accept certain restrictions as a result of their religious choice. Many had to pay taxes to support the established church despite their disagreements with it, and many were barred from holding public office.

Second, we need to recognize that the ratification of the First Amendment did not change any of this. It guaranteed only that the federal government would not establish an official national church or pass any laws interfering with a person’s religious practice. The states were left free to make their own rules about religion.

If we really get down to it, the First Amendment did not really do much at all in terms of altering the religious conditions of early America. It prevented the national government from creating a national church, but given all of the other contentious issues on the table during the nation’s first decades—slavery, the national debt, land policy, foreign attacks on American shipping—it is doubtful that anyone would have seriously tried to stir things up even further by seeking to impose a national religion. Similarly, while the First Amendment denied Congress all authority to interfere with the religious practices of the American people, Congress had little interest in doing this in the first place. Other issues were more pressing, and virtually everyone agreed that this sort of thing was better left to the individual states to handle.

So why, then, were the religious clauses even added to the First Amendment at all? That big question is addressed here. For now, let’s concentrate on what the religious protections of the First Amendment have come to mean over the past two centuries. Even though it can easily be argued that the lofty guarantees about religion in the First Amendment had very little practical effect in the first several decades of America’s existence, there is no denying that these clauses have since become hugely important—and hugely contentious—parts of our national experience.

First, a friendly reminder: there are actually two distinct clauses within the First Amendment involving religion. The first is the establishment clause. It specifies that Congress "shall make no law respecting an establishment of religion." The second is the free exercise clause. It specifies that Congress may not pass laws "prohibiting the free exercise" of religion. In the most basic terms, the establishment clause means Congress may not identify an official or national church or collect taxes or provide public money to support any specific religion; the free exercise clause means that Congress may not interfere with the manner in which any person chooses to worship.

But both of these clauses have come to mean a whole lot more. Whether the meaning eventually attached to these clauses is consistent with the original intentions of the founders is hard to gauge. (Again, get the full story here.) The early debates surrounding the creation of these clauses are not especially illuminating, nor did lawmakers or the courts clarify their meanings during the early years of the republic. The early religious controversies took place in the states that retained the authority to establish churches and pass laws pertaining to religion. The national government was largely immune from these controversies for almost a century; and consequently, there was little immediate attempt to clarify the full meaning of the First Amendment.

It was not until the second half of the nineteenth century that religious questions came before the United States Supreme Court, and they arrived there only because Mormons living in the Utah Territory engaged in polygamy, a marital practice that many in Congress found offensive. Since Utah was a territory with no state government to regulate its religious practices, and instead fell exclusively under the jurisdiction of Congress, Congress passed laws against polygamy—a practice defended by Mormons at the time as part of their religious observance—and forced the Court to sort out the free exercise clause for the first time.

The other event that forced the Supreme Court to think about the meaning of the First Amendment was the "incorporation" of the religious clauses in 1940. In that year, the Court ruled in Cantwell v. Connecticut that a local ordinance banning solicitation violated the religious rights of the Jehovah’s Witnesses that brought the suit. Even though this was a local ordinance, falling under a state’s jurisdiction, the Court ruled that the First Amendment was "incorporated" by the due process clause of the Fourteenth Amendment, and thus that the solicitation law should be overturned.