The story of Catholicism in America is deeply rooted in waves of immigration that followed well after Columbus. These waves are often remembered today in how American Catholics self-identify their ancestry, which we can measure in polls. For some there is no knowledge or memory of this and these people often just say they are of “American” ancestry. While others still deeply identify with the country of their grandparents or great grandparents, etc.
Yet when one looks at polling data on ancestry for Catholics there are always a few surprises. Perhaps the biggest is that Irish Americans are more likely to be Protestant than Catholic. This has been noted among academics (e.g., “How the Irish Became Protestant in America” by Michael Carroll in Religion and American Culture: A Journal of Interpretation, Vol. 16, No. 1 and “The Success and Assimilation of Irish Protestants and Irish Catholics in the United States” by Andrew M. Greeley in Sociology and Social Research, Vol. 72, No. 4) but is less well known among the media and general public who often assume that Irish and Catholic are virtually synonymous.
On average, only 35% of Americans who say they are of Irish ancestry self-identify their religion as Catholic. By comparison, nearly half of this group (47%) indicates their religion as Protestant.
The graph below shows the average percentage of adult Catholics in the United States who identify ancestry with countries that have had significant immigration to the Americas in the last 150 years. Each bar represents a decade average with the orange bar showing the last decade.
Overall, the biggest recent shift has been in the number of adult Catholics who self-identify their ancestry with a Latin American country and specifically with Mexico. We have commented elsewhere about the generational shift in the racial and ethnic composition of the Catholic population. Along with this change, Mexican ancestry has grown larger than Italian or Irish ancestry among American Catholics. In the most recent GSS survey, 69 percent of American adults of Mexican ancestry self-identified as Catholic.
Above photo courtesy of Dominic's pics at Flickr Creative Commons.