According to the U.S. Census Bureau’s 2006 American Community Survey, 36 million U.S. residents, or 12% of the population, claim Irish ancestry.

“This number is almost nine times the population of Ireland itself (slightly more than 4 million). Irish is the nation’s second most frequently reported ancestry, trailing only German.”

Massachusetts claims the highest population of Irish heritage with 24%.

Source: U.S. Census Bureau