While millions of people handle money on a daily basis, they rarely give the bills themselves a second thought. The American dollar is loaded with memorable symbols though: George Washington's formidable profile, the Great Seal of the United States (which is a bit mystical if you give it an eyeballing), and the proud bald eagle. And of course, boldly emblazoned across the back of the bill is the phrase "In God We Trust."
That common phrase may not have much impact on you, but for the Freedom From Religion Foundation (FFRF), it stands as a violation of the U.S. Constitution. In the First Amendment, the Establishment Clause prohibits the establishment of a national religion by Congress. That's why the FFRF (along with 19 other plaintiffs) is suing the U.S. Treasury, and has submitted a novel-sized complaint that illustrates the reasons why using the phrase on official currency is unacceptable.
FFRF Co-President Dan Barker says on the organization's website, "Our government is prohibited from endorsing one religion over another but also prohibited from endorsing religion over nonreligion. The placement of a monotheistic ideal on our nation's currency violates this structure and is therefore unconstitutional."
The plaintiffs supporting the cause say that the phrase "In God We Trust" discriminates against atheists and other citizens who do not believe in a god. Supreme Court Justice Sandra Day O'Connor said during the case of Lynch vs. Donnelly that the phrase "sends the message to members of the audience who are nonadherents that they are outsiders, not full members of the political community and an accompanying message to adherents that they are insiders, favored members of the political community.'
This is not the first time that people have taken offense to the presence of this phrase on money. A San Francisco atheist challenged it in 2010, but both of his legal appeals were rejected. The phrase "In God We Trust" has been on U.S. currency since 1864, and it replaced "E Pluribus Unum" as the official motto in 1956, a Latin phrase which translates to "One out of many."