It's been 60 years since the words "In God We Trust" were added to U.S. paper currency — a decision that has, in recent years, sparked intense controversy.
But the deep history behind how those words came to be enshrined in America's official motto is something that some might be relatively unfamiliar with.
While it is certainly true that the motto wasn't codified in U.S. law until President Dwight D. Eisenhower signed a joint resolution on July 30, 1956, the history actually runs much deeper than that.
In fact, the push for the official recognition of a higher power reportedly began during the Civil War-era after numerous appeals from the faithful flooded into the U.S. government. Some Americans at the time very clearly wanted officials to recognize and name God on U.S. currency.
The first of these petitions came in a letter dated Nov. 13, 1861 from the Rev. M.R. Watkinson of Ridleyville, Pennsylvania, to then-Treasury Secretary Salmon P. Chase, according to an official history published by the U.S. Treasury.
Watkinson wrote that he knew Chase would soon be submitting an annual report about the nation's finances to Congress, and implored him to consider the importance of appealing to God.
"One fact touching our currency has hitherto been seriously overlooked. I mean the recognition of the Almighty God in some form on our coins," Watkinson wrote, going on to encourage a design that included the words "God, Liberty, Law."
After offering up a detailed prospective inscription, the reverend continued, "This would make a beautiful coin, to which no possible citizen could object. This would relieve us from the ignominy of heathenism. This would place us openly under the Divine protection we have personally claimed."
That passionate appeal apparently had an impact, as Chase instructed the director of the U.S. mint to prepare a motto just weeks later.
"No nation can be strong except in the strength of God, or safe except in His defense," Chase wrote to the director. "The trust of our people in God should be declared on our national coins."
He continued, "You will cause a device to be prepared without unnecessary delay with a motto expressing in the fewest and tersest words possible this national recognition."
Congress soon passed the Coinage Act of 1864, which allowed for changes to coins; what followed was the appearance of "In God We Trust" on the two-cent coin that same year, according to the Treasury. In subsequent years, the motto was also placed on gold and silver coins, among others.
By 1938, all coins carried "In God We Trust," though it wasn't until 1956 that the four-word line became the official national motto of the U.S. Eisenhower's "In God We Trust" measure also ensured the line's placement on paper currency.
"Resolved by the Senate and House of Representatives of the United States of America in Congress assembled that the national motto of the United States is hereby declared to be 'In God We Trust,'" the joint resolution read.
Up to that point, the U.S. had embraced another motto — E Pluribus Unum, which is Latin for "out of many, one." That was essentially the nation's de facto motto until "In God We Trust" came on the scene.
According to the Treasury, "E Pluribus Unum" dates back to 1782, when it was mentioned in the Journals of the Continental Congress.
"'E Pluribus Unum' has appeared on coins since 1795 and has graced the back of $1 notes since 1935," the Treasury website reads. "The phrase has been required on all U.S. coinage by law since February 12, 1873."
It should be noted that Eisenhower had successfully urged for the inclusion of "under God" in the Pledge of Allegiance just two years before signing the "In God We Trust" resolution, according to History.com.
"In this way we are reaffirming the transcendence of religious faith in America’s heritage and future," Eisenhower said during a Flag Day speech in 1954, specifically referencing the Pledge. "In this way we shall constantly strengthen those spiritual weapons which forever will be our country’s most powerful resource in peace and war."
But that quest has proved contentious, as atheist activists have attempted to battle both the Pledge of Allegiance as well as the presence of "In God We Trust" on currency. Thus far, these efforts have been fruitless.
The Supreme Court has both denied review and dismissed cases brought by activist Michael Newdow in recent years. But in early 2016, Newdow once again filed suit in Ohio, arguing that the motto places Christians above atheists.
Local disputes were touched off in various communities across the country last year when many sheriffs' offices decided to add "In God We Trust" decals to government vehicles, leading to public showdowns with atheist groups.
Dan Barker, co-president of the Freedom From Religion Foundation, said last year that his organization was hoping that the decals could provide a way back in to suing over the motto. For now, though, the motto remains.