There's a lot of green around the U.S. on St. Patrick's Day, but only one town can be the "most Irish" and according to the 2010 census, that town is Butte.

According to irishcentral.com staff writer Kerry O'Shea in her article "Butte , Montana is the most Irish city according to 2010 U.S. Census," Butte has a record 23.6% of citizens that report being either Irish or Irish-American.

Interview with Kerry O'Shea:

Many assume that Boston would top the list, but it is only 19.8% Irish. It did however rank as the most Irish of America's 50 largest cities.

According to O'Shea, "Right behind Butte were Ocean City, N.J., Corinth, Miss., and Barnstable Town (better known as Cape Cod), Mass, all which had just over 20 percent identifying as being Irish-American."

Butte's Irish roots are deeply involved with the rise of the mining industry there. O'Shea says that Butte's embrace of Irish-Catholicism is a major reason why so many Irish families have decided to stick around. In the 1950's, the city boasted a total of 10 Catholic churches.