Taken from Wikipedia http://en.wikipedia.org/wiki/In_God_We_Trust
In God We Trust was adopted as the official motto of the United States in 1956. It is also the motto of the U.S. state of Florida. The phrase has appeared on U.S. coins since 1864 and on paper currency since 1957.[1] Its Spanish equivalent, En Dios Confiamos, is the motto of the Central American nation of Nicaragua.[2]
One possible origin of In God We Trust is the final stanza of The Star-Spangled Banner. Written in 1814 by Francis Scott Key (and later adopted as the U.S. national anthem), the song contains an early reference to a variation of the phrase: ”...And this be our motto: ‘In God is our trust’.”[3]
It was first used as a motto on coinage on the 1864 two-cent coin, followed in 1866 by the 5 cent nickel (1866–1883), quarter dollar, half dollar, silver dollar and gold dollars.[1][4] An 1865 law allowed the motto to be used on coins.[5] The use of the motto was permitted, but not required, by an 1873 law. While several laws come into play, the act of May 18, 1908,[6] is most often cited as requiring the motto (even though the cent and nickel were excluded from that law, and the nickel did not have the motto added until 1938). Since 1938, all coins have borne the motto.
On July 11, 1955, just one year after the phrase “under God” was incorporated into the Pledge of Allegiance,[7] 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.[1]
In 1956 the phrase was legally adopted as the United States’ national motto by a law passed by the 84th United States Congress.(Public Law 84–851)”,[8] and the United States Code at United States, now states: ”‘In God we trust’ is the national motto.”
Controversy
Some critics contend that the motto’s placement on money constitutes the establishment of a religion or a church by the government, thus violating the Establishment Clause of the First Amendment and the Separation of church and state. The motto was first challenged in Aronow v. United States in 1970, but the United States Court of Appeals for the Ninth Circuit ruled: “It is quite obvious that the national motto and the slogan on coinage and currency ‘In God We Trust’ has nothing whatsoever to do with the establishment of religion. Its use is of patriotic or ceremonial character and bears no true resemblance to a governmental sponsorship of a religious exercise.”[9] The decision was cited in Elk Grove Unified School District v. Newdow, a 2004 case on the Pledge of Allegiance. In Lynch v. Donnelly (1984), the Supreme Court upheld the motto because it has “lost through rote repetition any significant religious content”. So-called acts of “ceremonial deism” have supposedly lost their “history, character, and context”.[10] In Zorach v. Clauson, the Supreme Court has also held that the nation’s “institutions presuppose a Supreme Being” and that government recognition of God does not constitute the establishment of such a state church as the Constitution’s authors intended to prohibit. Constitutionalists object to sworn judiciaries employing historical context in what they believe ought to be a raw textual interpretation.[11][12] Some activists have been known to cross out the motto on paper money as a form of protest.[13] Although federal law (18 U.S.C. § 333 and 18 U.S.C. § 475) prohibits defacement of currency, it specifies either “intent to render such bank bill…unfit to be reissued” or a “notice or advertisement”, and no documented cases exist of prosecution for such action. Additionally, the Federal Reserve frequently recirculates similarly altered notes.[14]
Outside of constitutional objections, President Theodore Roosevelt took issue with placing the motto on coinage as he considered it sacrilegious to put the name of God on money.[15]