Within this collection are the Civil War 'Widows'' Pensions files, the Civil War Pensions Index, the Soldier Service Records, the 1860 US Census, the Southern Claims Commission files, and many other record sets. This is a collection of records all Irish genealogists should take a peep into, because thousands of Irish emigrants fought for the Union between 1861 and 1865. Most were born between 1820 and 1845, and most were already settled in the United States.
However, some actually left their homes, parents and siblings in Ireland to sign up for a soldier's pay, confident that their adventure would allow them to support their family back home.
To access the free collection, follow the link above and just start searching. If you don't already have an account or are not signed in, you'll be prompted to set up a free registered account as soon as you select a record to view. Only an email address and a password is requested.