After the battle of Antietam in 1862, Harriet Eaton traveled to Virginia from her home in Portland, Maine, to care for soldiers in the Army of the Potomac. Portland's Free Street Baptist Church, with liberal ties to abolition, established the Maine Camp Hospital Association and made the widowed Eaton its relief agent in the field. One of many Christians who believed that patriotic activism could redeem the nation, Eaton quickly learned that war was no respecter of religious principles.

Doing the work of nurse and provisioner, Eaton tended wounded men and those with smallpox and diphtheria...