Ballentine's Law Dictionary p28

FIRST AMENDMENT

1789
Written in 1787, ratified in 1788, and in operation since 1789, the United States Constitution is the world’s longest surviving written charter of government. Its first three words – “We The People” – affirm that the government of the United States exists to serve its citizens. The supremacy of the people through their elected representatives is recognized in Article I, which creates a Congress consisting of a Senate and a House of Representatives. The positioning of Congress at the beginning of the Constitution affirms its status as the “First Branch” of the federal government.

https://www.senate.gov/about/origins-foundations/senate-and-constitution/constitution.htm

TRIPOLI TREATY 1796

TREATY OF PEACE AND FRIENDSHIP. Concluded November 4, 1796;
​Ratification advised by the Senate June 7, 1797; proclaimed June 10, 1797.
ARTICLE XI.
As the Government of the United States of America is not in any sense founded on the Christian Religion; as it has in itself Religious freedom. no character of enmity against the laws, religion, or tranquility of Musselmen; and as the said States never have entered into any war or act of hostility against any Mehomitan nation, it is declared by the parties, that no pretext arising from religious opinions shall
ever produce an interruption of the harmony existing between the two countries.
​

1802 Jefferson's Letter to the Danbury Baptists

Supreme Court in 1878 and used to establish Separation of Church and State

Monte Mader