The number of Americans claiming Irishness as their ethnicity has dropped significantly, an analysis by the US Census Bureau has found, writes Sean O'Driscoll in New York.
While the Irish remain the second-largest ethnic group in the US, their overall percentage of the population dropped from 16 in 1990 to 11 in 2000, the report says.
The analysis is the first detailed breakdown of the ethnic origins of Americans who filled out the 2000 census. It found that the Irish remained the largest ethnic group in the north-east, while Germans remained the largest overall ethnic group.
Some 42.8 million Americans listed Germany as the country from which their ancestors came, while 30.5 million said their ancestors came from Ireland.
Latino and South American populations showed large increases, but respondents who listed "American" as their only ethnic background showed the single largest increase in numbers, reflecting both a lack of awareness of ethnic origins and a new patriotism in the American population.
The Census Bureau said it defines ancestry as a person's ethnic origin, heritage, descent or roots, which may include ethnic identities that have evolved in the United States. Many respondents listed more than one ethnic ancestry.
The report found that, while German, Irish and English remained the largest three European ethnic groups in the US, they had collectively decreased in size by at least eight million.
As a proportion of the population, German decreased from 23 per cent in 1990 to 15 per cent in 2000, while Irish ancestry decreased from 16 per cent to 11 per cent, and English from 13 per cent to 9 per cent.
The number of people who reported African American ancestry increased by nearly 1.2 million, or 4.9 per cent, between 1990 and 2000.
However, because of much larger increases in Latino, Chinese and other ethnic groups, the percentage of African Americans in the overall population decreased slightly over the decade, from 9.5 per cent to 8.8 per cent.