Well, in answer to your question, several women actively participated in the Civil War.
The one that comes immediately to mind is Mary Walker. She's important because she's the only woman ever to be awarded the Congressional Medal of Honor. As you know, this medal is given to people who've served the United States with exceptional bravery. In addition, she was the only female physician in either of the two armies that fought in that war. Even though she had two medical degrees, many officers made her life difficult because they didn't believe that a woman should be a doctor. However, she refused to back down and leave the army. In fact, she risked her life several times during the war and was even captured at one point, but she was soon released. Umm, after the war, she was arrested several times for wearing pants. And although Congress eventually tried to take her medal away, she refused to give it back and continued to wear it wherever she went.