Established Religion in the United States -- What I didn't Know

I had not realized that, although the First Amendment to the United States Constitution explicitly forbids the federal government to establish a state religion, some individual states did have state religions in 1789. Wikipedia tells me

Connecticut continued to do so until it replaced its colonial Charter with the Connecticut Constitution of 1818; Massachusetts did not disestablish its official church until 1833, more than forty years after the ratification of the First Amendment; and local official establishments of religion persisted even later.

Wikipedia also informs me that

The Fourteenth Amendment to the US Constitution, ratified in 1868, makes no mention of religious establishment, but forbids the states to "abridge the privileges or immunities" of U.S. citizens, or to "deprive any person of life, liberty, or property, without due process of law". In the 1947 case of Everson v. Board of Education, the United States Supreme Court held that this later provision incorporates the First Amendment's Establishment Clause as applying to the States, and thereby prohibits state and local religious establishments. The exact boundaries of this prohibition are still disputed, and are a frequent source of cases before the US Supreme Court — especially as the court must now reconcile this post-1947 view with the original First Amendment clause that explicitly prohibits any restraint on the free exercise of religion.

While deemed unconstitutional now, several states still have on their books religious qualifications requirements to hold public office.