Answer: E pluribus unum was considered the de facto motto until 1956 when the United States Congress passed an act adopting “In God We Trust” as the official motto.
In the late 18th century our young country was fighting a war for independence against Great Britain, who at the time was allied with France. Starting around the mid-point of the 1760s, there were growing philosophical and political differences which strained the relationship between Great Britain and its colonies. Patriot protests against taxation without representation followed the Stamp Act and escalated into boycotts, which culminated in 1773 with the Sons of Liberty destroying a shipment of tea in Boston Harbor. After Britain responded by closing the Boston Harbor, Massachusetts colonists created the Suffolk Resolves and established a shadow government. Meanwhile, twelve of the colonies formed a Continental Congress to coordinate their resistance, establishing committees and conventions that effectively seized power. After open combat in 1775 and a British evacuation of Boston in March of 1776, the Second Continental Congress voted for independence on July 2, 1776, and ultimately issued its declaration on July 4.
One of the many things happening during this time was deciding which motto to choose for our newly formed country. In 1776 Pierre Eugene du Simitiere suggested to the committee responsible for developing the seal that we use “E Pluribus Unum”, Latin for “Out of many, one”. At the time of the American Revolution, the thirteen-letter motto was the exact phrase that appeared prominently on the title page of every issue of a popular periodical, The Gentleman’s Magazine, which collected articles from many sources into one magazine. This idea struck Simitiere as very fitting given how the thirteen colonies were making an effort to become one. The meaning of the phrase originates from the concept that out of the union of the original Thirteen Colonies emerged a new single nation. It is emblazoned across the scroll and clenched in the eagle’s beak on the Great Seal of the United States. Below is the original 1776 design for the Great Seal by Simitiere. The shields with 13 initials of the colonies linked together with the motto.
This motto didn’t last forever, though. You see, if we fast forward 180 years to 1956 we learn that the United States government adopted “In God We Trust” as the official motto replacing E Pluribus Unum. This phrase originally appeared on the two-cent piece in 1864 but there was something extremely important happening during the 1950s that helped enshrine this motto into law: the Cold War. During the Cold War era, the government of the United States sought to distinguish itself from the Soviet Union, which promoted state atheism and thus implemented antireligious legislation. With that said, the 84th Congress passed a joint resolution “declaring IN GOD WE TRUST the national motto of the United States”. The resolution passed both the House and the Senate unanimously and without debate. The law was signed by President Eisenhower on July 30, 1956, along with a law that required “In God We Trust” be printed on all U.S. currency and coins.