...never before has the Crescent City been sung as the birthplace of the man who first brought Craps to America. And yet to Bernard Xavier Philippe de Marigny de Mandeville, born in New Orleans in 1785, belongs this honor. A swaggering, gallant, fantastic figure, this son of a wealthy Creole planter was left at sixteen a fabulously rich orphan. His every whim indulged while his father was alive, he became as wild and headstrong after his death as an unbacked mustang, and his guardian, abandoning all idea of control, finally shipped him to England, hoping that life abroad might mend his manners; but in London Bernard's dissipations became only more pyrotechnic, and he spent most of his time at Almack's and other famous gambling places where a novel dice ga me from France, called Hazard, was all the rage. Bad reports of his dissolute living and phrenetic gambling came to his guardian's ears and Bernard was ordered home, where he immediately taught his Creole friends this new alluring game.

...The Americans ... looked down upon the Creoles as an effete, alien race and called them "Johnny Crapauds" a term of reproach the British had long fastened upon the French because of their supposed predilection for frogs as an article of diet.

When the Yankees saw the Creoles huddled about a table excitedly playing Marigny's new game of Hazard, wagering money, slaves, plantations, and even dull gold mistresses on the turn of the dice, they slurringly referred to the pastime as "Johnny Cr apaud's" game. It's popularity, however, spread like yellow fever in a mosquito swamp. Before long it became the passionate obsession of the whole town, of Americans and Creoles alike, and was rechristened, so it was said, "crapaud's" and later abbreviate d to "craps."

[Edward Larocque Tinker, The Palingenesis of Craps (New York, 1933), pp. 1-3]

 

From http://nutrias.org/exhibits/french/craps.htm