January 1995: A committee of parents concerned about the need for Godly, high school level academic training began meeting to lay the groundwork for a Christian high school in Bartlesville. Under the joint sponsorship of Grace Baptist and Westminster Presbyterian churches, American Christian School began with four freshmen students that fall. They met in the home of Mark and Cathy Archambo.
January 1996: The school board was established.
1996/1997: ACS moved into the building of Grace Baptist Church on Kaw Street.
1997/1998: The students chose the Patriots as the school mascot and red, white and blue as the school colors.
Summer 1998: The classical method of education was embraced.
1999/2000: The school began occupying the upstairs of Virginia Avenue Baptist Church.
2000/2001: ACS became a K-12th grade school. A debate team was formed.
November 2002: The school moved into the newly renovated building that was formerly the Moose Lodge on Highway 75.
May 2008: ACS received accreditation through the Association of Christian Teachers and Schools (ACTS).
June 2012: ACS because Coram Deo Classical Academy to communicate the fact that it is a classical Christian school. Coram Deo, a Latin phrase translated "in the presence of God", summarizes the idea of Christians living in the presence of, under the authority of, and to the honor and glory of God. The school also relocated to the education building on the campus of Virginia Avenue Baptist Church.