Yes, it goes with civil war. It is harder to find but some places sell FQ packs with shirtings. They are what shirts where made off. Once you know what they are you'll notice them in reproduction style quilts.
http://www.reproductionfabrics.com/lines.php?subcat=963
Here is just a link with some fabrics like that. Atleast that is what I understand to be shirtings. I thought Bonnie Hunts was a little different. Plaid shirts that are recycled to make quilts? Maybe some one else can clarify.