The Passano Collection consists of over four hundred books and articles. It contains many first hand accounts, mostly written by women, more about life and the hardships endured during the war than about battles. Included are stories of refugees and prisoners of war, and of women who disguised themselves as soldiers to participate in the fighting. There are novels, some contemporary, as well as poetry, published diaries and letters, and a pictorial history. Several titles discuss the slave trade and the southern social climate before the war. Publication dates range from 1837 to 1994, and there are a number of delightful, well-preserved Victorian cloth bindings.

Cataloged articles published between 1863 and 1988 in journals of historical societies and a few government documents help to illustrate local interest, such as one about the Civil War camps in Baltimore County and the story of a courtship between two Rockville residents during the war. Military history is represented primarily by the accounts of blockade-runners, the thirty-one volume set of Official Records of the Union and Confederate Navies in the War of the Rebellion, a few biographies of officers, and the forty-three volume set of The Confederate Veteran Magazine.