Don't feel dumb at all. Unless you study vintage textiles, you probably wouldn't recognize the patterns and colors as being from that time frame. Even those of us who study vintage textiles need to research specific fabrics. Some time frames are easier to recognize on sight than others. For me, 1930's and 1880's are easy. Civil War, not as easy for me---maybe with more study, someday...
If you are looking to buy some CW reproductions, also look on etsy. There are lots for sale there, and some are really a great bargain! I'm guilty of spending waaay too much there!