There's a wine company in Duplin County, North Carolina called the Duplin Winery. They make rather sweet wines that I personally enjoy. They tend to make sweet wines, and they make two sparkling wines, one of which is sold as champagne.
first, it has to be a champagne, wine is not acceptable. second, try a zip and if its sweet, than you almost get the right one. third, check the bottle, when it has a brand marked on the bottle.... bingo.