Found: A sci-fi series where civil war soldiers are portaled to another planert

Please help me find this series. If I'm remembering it right, a civil war ironclad ship is transported to a planet where there are evil aliens that show up every 20 or so years and eat a tenth of the human population. The civil war soldiers bing lots of tech to the other humans that had been brought to this world hundreds of years earlier, guns and trains and other things, but then the aliens arrive and they must fight. I believe the authors name begins with a W but I'm lost trying to find it. Series is at least 5 books long. Thank you.

I think this might be the Lost Regiment series by William R. Forstchen. I haven't read it, but the description of the first book sounds like it should fit.

Yes!! Thank you, I knew it had a William in it, but I thought that was the surname. Thanks so much, you were super quick.