While the First Amendment undoubtedly was intended to preclude the government from establishing a national religion as you note, that was hardly the limit of its intended scope. The first Congress debated and rejected just such a narrow provision (“no religion shall be established by law, nor shall the equal rights of conscience be infringed”) and ultimately chose the more broadly phrased prohibition now found in the Amendment. During his presidency, Madison vetoed two bills, neither of which would form a national religion or compel observance of any religion, on the ground that they were contrary to the establishment clause. While some in Congress expressed surprise that the Constitution prohibited Congress from incorporating a church in the town of Alexandria in the District of Columbia or granting land to a church in the Mississippi Territory, Congress upheld both vetoes. Separation of church and state is hardly a new invention of modern courts. In keeping with the Amendment’s terms and legislative history and other evidence, the courts have wisely interpreted it to restrict the government from taking steps that could establish religion de facto as well as de jure. Were the Amendment interpreted merely to preclude government from enacting a statute formally establishing a state church, the intent of the Amendment could easily be circumvented by government doing all sorts of things to promote this or that religion–stopping just short of cutting a ribbon to open its new church.