Final answer:
There are currently 33 million Americans who claim Irish ancestry, making Irish Americans one of the prominent ancestry groups in the country.
Step-by-step explanation:
According to demographic information and historical records, Irish Americans are one of the leading ancestry groups in the United States. With 33 million Americans claiming some degree of Irish ancestry, there are now more Irish Americans in the United States than there are people living in Ireland. This number represents a significant cultural group that has progressively integrated and assimilated into the broader American society. In the past, the proportion of Americans claiming their Irish heritage was much smaller, particularly in certain regions of the U.S. However, over time and particularly towards the end of the 19th century, the number of Americans with Irish ancestry grew, reflecting the broader trend of immigration into the United States and the mixing of ancestries that led many to adopt a simple 'American' identity, especially those whose families have been in the U.S. for several generations.