books.google.ca - Some 150,000 Irish-American immigrants served in the Union Army, most of them from Boston, New York and Chicago, and about 40,000 fought in the Confederate Army. The best known unit was the Irish Brigade of the Union Army of the Potomac, which distinguished itself at Antietam and, particularly, at Fredericksburg,...http://books.google.ca/books/about/Irish_American_Units_in_the_Civil_War.html?id=-I4670AlaYwC&utm_source=gb-gplus-shareIrish-American Units in the Civil War
