The Pledge of Allegiance was first written in 1892 for a magazine contest, and it read: "I Pledge Allegiance to my Flag and the Republic for which it stands; one nation indivisible, with liberty and justice for all." The Pledge became part of the US Flag Code in 1942, and in 1954 President Eisenhower and Congress added the phrase "under God” into the Pledge.
Proponents of including "under God" in the Pledge argue that the United States is a Christian nation, at least 80% of Americans support the phrase, the language reflects America’s civic culture and is not a religious statement, and federal law, state constitutions, and US currency already contain references to God.
Opponents contend that church and state should be kept strictly separate as the Founding Fathers intended. They argue that the Constitution protects minority rights against majority will, and that the words "under God" in the Pledge are a religious phrase and thus violate the Establishment Clause of the First Amendment.
Under God in the Pledge ProCon.org is a nonpartisan, nonprofit website that presents research, studies, and pro and con statements on questions related to religion and the pledge of allegiance in the US.