"In God We Trust" was adopted as the official motto of the United States On
July 11, 1954, just one month after the phrase "under God" was incorporated
into the Pledge of Allegiance. The U.S. Congress enacted Public Law 84-140,
which required the motto on all coins and currency. The law was approved by
President Eisenhower on July 30, 1956, and the motto was progressively added
to paper money over a period from 1957 to 1966.