Okay, so a long time ago in the United States, women weren't really allowed to fight in wars. People thought that fighting was just for men because they were stronger and tougher. But some women really wanted to help out and fight for their country too.
One way that women helped was by being nurses. They would take care of the soldiers who got hurt during battles. Some women even disguised themselves as men so they could fight in the war. They would cut their hair short and wear men's clothes so nobody could tell they were women.
During the American Revolution, a woman named Deborah Sampson dressed up as a man and fought in the army. She was injured a few times, but nobody found out she was a woman until she got sick and needed to see a doctor. After that, people found out she was a woman, but they still thought she was really brave for fighting.
Even though some women were able to fight in wars, it wasn't until almost 100 years later that the government officially allowed women to be in the army. In 1862, there was a Civil War and some women were finally allowed to work as nurses and spies for the army. They would sneak around and try to find out information that would help their side win.
Eventually, even more women started joining the military. They would work as manual laborers, cooks, and nurses. Some would even help out in combat, but they still weren't allowed to officially be in the army until much later.
So, before 1900, women were able to help out in wars, but it wasn't until much later that they were officially allowed to be in the military and fight alongside men. But even though they weren't officially recognized, many women still showed their bravery and helped their country in times of war.