The United States has long been proud of its separation between church and state, but perhaps one exception is the motto “IN GOD WE TRUST” on American coinage. Prior to the Civil War, American coins typically displayed the word “LIBERTY” and little more in the way of messages, legends or mottos. Symbols of unity (like interlocked links on the 1793 Chain Cent) or tradition (13 stars to honor the original colonies) were often implemented, but verbal messages were unusual.

Public sentiment changed rapidly in the 1860s with the onset of the Civil War. Americans became much more religiously oriented during the war—and some wanted to declare that God was on the side of the Union. In 1861, a reverend petitioned US Treasury Secretary Salmon P. Chase to add a statement recognizing God on American coinage. Surprisingly, Chase agreed and directed US Mint director James Pollock to add a motto or emblem along these lines to our money.

There was some debate as to which phrase to use. One of the original phrases proposed was “In God Is Our Trust” but this exact motto never found its way onto an actual coin. A few pattern coins exist with the motto “God Our Trust” but this version was apparently nixed as well. Finally, Secretary Chase recommended “In God We Trust,” which was eventually adopted.

Initially, the phrase was only added to one-cent and two-cent coins in 1864, but in 1865 Congress officially approved the motto for all United States coins. In God We Trust was added to the Quarter, Half Dollar, Silver Dollar, Half Eagle, Eagle and Double Eagle in 1866—and in the process some interesting transitional rarities were created. For instance, somehow just one 1866 No Motto proof Silver Dollar was made in 1866; the coin is valued well in excess of $1 million.

The use of “In God We Trust” was interrupted somewhat in ensuing years; it briefly vanished off the $10 and $20 gold pieces after they were redesigned by Augustus St. Gaudens. After tremendous public outcry, the motto was not only added back to these two gold coins, but Congress also made the phrase mandatory for coins on which it previously appeared. Finally, in 1938, Congress ordered that every coin display the phrase, including those where it had previously never appeared (like the penny). This order still remains in effect for every United States coin.