I think this is Marshall's Dry Goods. They have their own fabric line, and I'm not sure if it is sold in stores or not. I would contact them directly. Here's a link to their site:
http://www.marshalldrygoods.com/
I have ordered from them before. I think it's a very nice line of fabric, but wouldn't call it LQS quality. Nicer than a lot of that thin stuff at the big box stores and you sure cannot beat their prices.