You would legitimately be stunned to find what the American government and politicians did that was overtly and explicitly Christian when our nation was founded.
- The first English Bible ever printed in America was funded and commissioned by Congress.
- One of Congress' first acts was to select and pay Christian ministers as chaplains
- Congress designated the House chamber for weekly Christian worship services in the capital building
- This was the prayer at the first Continent Congress:
"The prayer at the first Continental Congress on September 7th 1774: O Lord our Heavenly Father, high and mighty King of kings, and Lord of lords, who dost from thy throne behold all the dwellers on earth and reignest with power supreme and uncontrolled over all the Kingdoms, Empires and Governments; look down in mercy, we beseech Thee, on these our American States, who have fled to Thee from the rod of the oppressor and thrown themselves on Thy gracious protection, desiring to be henceforth dependent only on Thee. To Thee have they appealed for the righteousness of their cause; to Thee do they now look up for that countenance and support, which Thou alone canst give. Take them, therefore, Heavenly Father, under thy nurturing care; give them wisdom in Council and valor in the field; Defeat the malicious designs of our cruel adversaries; Convince them of the unrighteousness of their Cause & if they persist in their sanguinary purposes, O! let the voice of Thine own unerring justice, sounding in their hearts, constrain them to drop the weapons of war from their unnerved hands in the day of battle! Be Thou present, O God of wisdom, and direct the councils of this honorable Assembly; enable them to settle things on the best and surest foundation. That the scene of blood may be speedily closed; that order, harmony and peace may be effectually restored, and truth and justice, religion and piety, prevail and flourish amongst Thy people. Preserve the health of their bodies and vigor of their minds; shower down on them and the millions they here represent, such temporal blessings as Thou seest expedient for them in this world, and crown them with everlasting glory in the world to come. All this we ask in the name and through the merits of Jesus Christ, Thy Son and our Savior. Amen."
- Etc.
It's not a departure from the original norm for the US government to openly treat Christianity as true; it has been a departure from the norm for the US government *not to* for the last ~80 years