In principle say that gringo is used as a derogatory way to call abroad, that is not understood you when speaks, and is usually Latin use (in the broad sense of the word) people of Northern origins. There are several versions about its etymology; but the less credible is the green go home, not only because the phrase was not used in the mid-19th century, but because the Mexican people did not speak English, but if you listened to it, and there is some documentation about a tune singing us soldiers and qu and he said Green grow the bushes, whose first syllables rather poorly understood by those who spoke Spanish ended up in the word gringo. Actually the term used before in Spain, where speaking in gringo already was a vulgar way to say to speak in Greek (for being incomprehensible and distant to the Spanish language); call gringo a strange or alien there is a short passage.
GRINGO-During the punitive expedition that American troops began looking for the unique invader us have had, whose name was Francisco Villa ( Doroteo Arango ). The population see this military force shouted them "GRINGOS ". Apparently the first syllable was referring to the colour of the uniform of the invading (GREEN = GREEN ) the second part is aludia to GO, which means go.