“In God We Trust” became the official national motto of the United States in 1956.
Congress adopted the phrase as the national motto through a joint resolution signed by President Dwight D. Eisenhower on July 30, 1956. The wording had appeared on U.S. coins before then, beginning with the two-cent coin in 1864 during the Civil War era.
The phrase also became associated with paper currency later. “In God We Trust” first appeared on U.S. paper money in 1957, beginning with the one-dollar silver certificate, and it was gradually added to Federal Reserve notes.
The older Latin phrase “E pluribus unum,” meaning “Out of many, one,” remains on the Great Seal and appears on many coins. That history explains why the two phrases are sometimes confused, even though only “In God We Trust” is the statutory national motto.