In order to order a pension from the National Archives it helps to know some details about the unit in which your ancestor served. Genealogists who are trying to pinch pennies, now have one more source to help them find if their ancestor got a pension from the federal government.
www.footnote.com
Footnote does charge, however, you can view some information at no charge...just not the images. Footnote has the Regimental Index to Union Civil War pensions on their site. Viewing the cards on the site is NOT free and requires a membership or a fee per image. However, the citation listed underneath the card is free and is enough to allow you to order a pension from the National Archives. And if your guy is in the index of pensions, then he obviously has a pension.
The image here is one you would need a membership to view, but the "citation" below the image would be enough to order the pension from the National Archives.
There are other finding aids for Civil War information, some of which are free and some of which are not. Our page of Civil War pension information has links to these sites and some articles about obtaining and using Civil War pension records.