One of the ads appears in Charlotte on the Billy Graham Parkway.
The $15,000 ad campaign was launched this week by the North Carolina Secular Association, just weeks before Independence Day.
The group touts itself as consisting of "your friends and family, your neighbors and co-workers."
"Whether you are religious or not we ask you to help end official discrimination and personal prejudice against your secular neighbors because of what we believe ... or don't believe," the group states.
The words "under God" were added to the pledge in 1954. Sacramento atheist Michael Newdow made several attempts in court to remove the terms but failed each time. Most recently, the U.S. Court of Appeals for the Ninth Circuit ruled in March that as a whole, the pledge "is an endorsement of our form of government, not of religion or any particular sect." When the pledge was amended in 1954, Congress' predominant purpose was "patriotic, not religious," Judge Carlos Bea wrote for the majority.
But Joseph McDaniel Stewart, vice president of FreeThoughtAction, which contributed funds for the ad campaign in North Carolina, argues that when the terms "under God" were inserted between "one nation" and "indivisible," "they made a lie out of both those ideals because you can't have an indivisible nation if you draw a line between the godly and godless."
Secular and nontheist groups are particularly concentrating their efforts on North Carolina where public officials must hold to a belief in God.
The state constitution states: "The following persons shall be disqualified for office: First, any person who shall deny the being of Almighty God."
"Even if this requirement can't be enforced because it violates the U.S. Constitution, it's still there," said William Warren of the Charlotte Atheists & Agnostics, in a statement.
North Carolina, home to world renowned evangelist Billy Graham, is one of the most religious states in the country, according to the Pew Forum on Religion & Public Life. Eighty-one percent say they believe in God with absolute certainty, 69 percent say religion is very important in their lives, 68 percent pray at least once a day, and 49 percent attend religious services at least once a week. The data comes from the Pew Forum's 2007 U.S. Religious Landscape Survey.
The North Carolina Secular Association is appealing to both non-religious and religious North Carolinians to remove references to God in the pledge, the state constitution, and also the national motto ("In God We Trust").
The group's ads are currently up in Charlotte, Winston-Salem Area, and Greensboro.