A traditional Irish hat is a rounded wool cap with a stiff brim at the front. Modern flat caps are generally cotton, leather or tweed hats. The origins of the flat cap lie with 14th century Ireland yet there are some sources that claim the cap was worn before that in some parts of Itlay and the UK.
The flat cap arrived to the United States with the Irish immigrants. Throughout the United States, young boys were known to wear the flat cap during the late 19th and early 20th century. But it was not quite as popular in America back then as it was across the pond. The cap was worn by very few people in America during the late 1800's. However, in the early 1900's, Irish hats, particularly tweed hats began to grow in popularity across the country and became standard wear for boys in the 1910's. During the 1910's and 1920's flat caps were also quite popular among men who wore knicker suits. The flat cap is often associated with the newsboys of America. Newsboys were the boys who stood on the street corners selling newspapers and their flat cap became known as the newsie's cap or a newsboy.
In modern times traditional Irish hats are considered to be somewhat fashionable and are worn within many different cultures and classes throughout the United States, ranging from the men and women of America's Heartland who raise the country's livestock and grow its crops, to celebrities such as Brad Pitt and George Clooney who are regularly seen donning the flat cap. Traditional blue collar cities such as Boston have adopted the cap as their own, where it is known as a 'Scally Cap'. For more information check out http://www.bostonscally.com/blogs/news/tagged/blue-collar-culture
