July 11, 2009. Exactly today, the United States legislation approved the appearance of the motto “In God We Trust” on all coins and paper currency of the United States.
The motto: "In God We Trust". Source: http://z.about.com/d/coins/1/5/W/-/-/-/Coin-anatomy-3.jpg
The motto, was seriously considered after a first letter of appeal by Rev. M.R. Watkinson (Minister of the Gospel from Ridley Township, Pennsylvania) to Secretary of Treasury Salmon Chase.
In Reverend Watkinson’s letter, he said that putting the motto on the U.S. coins means “recognizing God in the country” while “relieving the Americans from the ignominy of heathenism”.
Reverend Watkinson’s strongly worded letter prompted Secretary Chase to instruct Director of the Mint at Philadelphia James Pollock on Nov. 20, 1861 “to prepare without unnecessary delay with a motto expressing in the fewest and tersest words possible this national recognition.”
And the rest, as they say, is history.
Sources: http://en.wikipedia.org/wiki/In_God_We_Trust
http://www.treas.gov/education/fact-sheets/currency/in-god-we-trust.shtml