This is a really interesting column written by Pat McNamara, a Catholic Historian, on how despite the anti-Catholic feelings in the country at the time, Catholic nuns were extremely active as nurses on both sides of the Civil War.
An excerpt:
“On the battlefields and in the hospitals, soldiers on both sides of the Civil War owed their consolation, and sometimes their limbs or their very lives, to the Catholic Nun.”
Full Article: Catholic Sisters and the American Civil War