The story
The concept goes back to the 19th century, but was popularized in its current form by sociologist Robert Bellah in his 1967 article "Civil Religion in America".
Etymology from Wiktionary, CC BY-SA 4.0.
American civil religion
Today it means: An interpretation of the United States' Christian-derived values and nationalist attitudes as a monotheistic nonsectarian civil religion that fosters social and cultural integration. Full definition →