Although not an “official” holiday in the United States, St. Patrick’s Day has a long history of being celebrated with parades and general goodwill for all things Irish. The day commemorates St. Patrick, who introduced Christianity to Ireland in the fifth century. Because many Americans celebrate their Irish lineage on St. Patrick’s Day, March was picked as Irish-American Heritage Month. The month was first proclaimed in 1995 by Congress. The U.S. president also issues an Irish-American Heritage Month proclamation.

Population Distribution
34.0 million
Number of U.S. residents who claim Irish ancestry. This number is almost nine times the population of Ireland itself (3.9 million). Irish is the nation’s second most frequently reported ancestry, trailing only German.
<http://www.census.gov/acs/www/Products/Profiles/Single/2003/ACS/Tabular/010/01000US2.htm>
<http://www.census.gov/ipc/www/idbsum.html>

24%
Percentage of Massachusetts residents of Irish ancestry — about double the national percentage.
<http://www.census.gov/acs/www/Products/Profiles/Single/2003/ACS/Tabular/040/04000US252.htm>

3
Number of states in which Irish is the leading ancestry group: Delaware, Massachusetts and New Hampshire. Irish is among the top five ancestries in every state but two (Hawaii and New Mexico).
<http://www.census.gov/Press-Release/www/releases/archives/census_2000/001870.html>

54
Number of counties where Irish is the largest observed ancestry group. Forty-four of these counties are in the Northeast, with 14 in New York, 11 in Massachusetts and five in New Jersey. (The number of people of Irish ancestry in a county may not be significantly different from the number of people of other ancestries in the county.) (From unpublished data.)

348,978
Number of Middlesex County, Mass., residents who are of Irish ancestry. Among the 54 counties where Irish is the largest observed ancestry group, Middlesex had the highest population of Irish-Americans, with Norfolk County, Mass., second, with 203,285. (From unpublished data.)

31%
Percentage of the population of Plymouth County, Mass., and Norfolk County, Mass., that is of Irish ancestry. Among the 54 counties where Irish is the largest observed ancestry group, these two counties had the highest rate. (From unpublished data.)

Coming to America
148,000
Number of foreign-born U.S. residents born in Ireland.
<http://factfinder.census.gov/servlet/DatasetMainPageServlet?_program=ACS&_lang=en&_ts=123760283921>

4.8 million
Total number of immigrants from Ireland admitted for lawful permanent residence since fiscal year 1820, the earliest year for which official immigration records exist. By fiscal year 1870, about half of these immigrants were admitted for lawful permanent residence. Only Germany, Italy, the United Kingdom and Mexico have had more immigrants admitted for permanent residence to the United States than Ireland. <http://149.101.23.2/graphics/shared/aboutus/statistics/2003Yearbook.pdf>

1,010
Total number of immigrants from Ireland admitted for lawful permanent residence to the United States in the 2003 fiscal year.
<http://149.101.23.2/graphics/shared/aboutus/statistics/2003Yearbook.pdf>

Trade With the “Old Sod”
$23.0 billion
The value of U.S. imports from the Republic of Ireland during a recent 10-month period (January-October 2004). Meanwhile, the United States exported $6.6 billion worth of goods to Ireland.
<http://www.census.gov/foreign-trade/www/>

Places to Spend the Day
4
Number of places in the United States named Shamrock, the floral emblem of Ireland. Mount Gay-Shamrock, W.Va., and Shamrock, Texas, were the most populous, with 2,623 and 1,828 residents, respectively. Shamrock Lakes, Ind., had 164 residents and Shamrock, Okla., 126. (Figure for Mount Gay-Shamrock is a Census 2000 count; the other figures in this paragraph are 2003 estimates.)
<http://factfinder.census.gov/home/saff/main.html?_lang=en>
<http://www.census.gov/Press-Release/www/releases/archives/population/001856.html>

9
Number of places in the United States that share the name of Ireland’s capital, Dublin. Since Census 2000, Dublin, Calif., has surpassed Dublin, Ohio, as the most populous of these places (35,581 compared with 33,606 as of July 1, 2003).
<http://factfinder.census.gov/home/saff/main.html?_lang=en>
<http://www.census.gov/Press-Release/www/releases/archives/population/001856.html>

If you’re still not into the spirit of St. Paddy’s Day after stopping by one of the places named “Shamrock” or “Dublin,” then you might consider paying a visit to Emerald Isle, N.C., with 3,528 residents, of whom a ratio of 1-in-6 are of Irish descent.
<http://factfinder.census.gov/home/saff/main.html?_lang=en>
<http://www.census.gov/Press-Release/www/releases/archives/population/001856.html>

The Celebration
22
The number of gallons of beer consumed per capita by Americans annually. On St. Patrick’s Day, some drinking establishments offer green-dyed beer to their thirsty patrons. See Table 201, Statistical Abstract of the United States: 2004-2005
<http://www.census.gov/prod/www/statistical-abstract-04.html>

376
Number of breweries in 2002, down from 529 in 1997. These figures do not count microbreweries or brewpubs that serve customers on the premises. The nation’s breweries are the source for the domestic beer that is often an integral part of St. Patty’s Day celebrations. While California had the highest number of breweries (55), Colorado had the largest number of brewery employees, with more than 5,000.
<http://www.census.gov/prod/ec02/ec0231i312120.pdf>