And the Establishment Clause has been in the US Constitution from the beginning, because the Founders didn't want Protestants, Catholics, Muslims, or any other religion to be seen as favored by the US government, to keep religious strife and political issues stemming from religion from tainting the US gov.
Since Bear Ribs is handling the double-standards with Islam in schools, I'll handle this side of things.
This article covers things fairly well:
Many people are surprised to learn that the United States Capitol regularly served as a church building; a practice that began even before Congress officially moved into the building and lasted until well after the Civil War. Below is a brief history of the Capitol's use as a church, and some of...
wallbuilders.com
Some key excerpts:
"Then, on December 4, 1800, Congress approved the use of the Capitol building as a church building. The approval of the Capitol for church was given by both the House and the Senate, with House approval being given by Speaker of the House, Theodore Sedgwick, and Senate approval being given by the President of the Senate, Thomas Jefferson."
(
Debates and Proceedings in the Congress of the United States (Washington: Gales and Seaton, 1853), p. 797, Sixth Congress, December 4, 1800.)
"City of Washington, June 19. It is with much pleasure that we discover the rising consequence of our infant city. Public worship is now regularly administered at the Capitol, every Sunday morning, at 11 o’clock by the Reverend Mr. Ralph. "
(
Federal Orrery, Boston, July 2, 1795, p. 2. )
"Significantly, Jefferson attended that Capitol church service just two days after he penned his famous
letter containing the “wall of
separation between church and state” metaphor. "
"U. S. Rep. Manasseh Cutler, who also attended church at the Capitol, recorded in his own diary that “He [Jefferson] and his family have constantly attended public worship in the Hall.”
7 Mary Bayard Smith, another attendee at the Capitol services, confirmed: “Mr. Jefferson, during his whole administration, was a most regular attendant.”
8 She noted that Jefferson even had a designated seat at the Capitol church: “The seat he chose the first Sabbath, and the adjoining one (which his private secretary occupied), were ever afterwards by the courtesy of the congregation, left for him and his secretary.”
9 Jefferson was so committed to those services that he would not even allow inclement weather to dissuade him; as Rep. Cutler noted: “It was very rainy, but his [Jefferson’s] ardent zeal brought him through the rain and on horseback to the Hall.”
10 Other diary entries confirm Jefferson’s attendance in spite of bad weather.
11"
This is particularly relevant, because
Thomas Jefferson himself was not actually a Christian. Yet he held that Christian ethos and community was so crucial to a healthy society, that he would attend, because he believed that if he expected other citizens to follow and uphold Christian values, he must set an example of doing so himself.
To make it clear,
Even the most outspoken agnostic/gnostic among the Founding Fathers supported and actively participated in church services within government buildings.
The idea that the establishment clause bars practice of Religion by government employees is
wholly an invention of the modern secular left and atheists, and is specifically trying to weaponize that in order to drive Christianity out of government, so that they can control all institutions and levers of power.