Respuesta :
Depending slightly on which period of American history you're referring to, the best option would be "Ireland," since it was from this country that the US saw the most immigration for quite some time.
From 1820 to 1860 the most numerous number of immigrants coming to the United States came from Ireland because of the hard living conditions they suffered in their country and the famine that affected them, also known as The Great Hunger. Sadly, plenty of them died on the way to the United States, which is why their ships were called coffin ships. At first, most of them located around port cities to work in construction and lumbering, but once they had a better economy, they moved inland.