LIzzie is very excited when her cousin Rosanna, a year older than her, moves to Gettysburg to live with Rosanna's sister. Lizzie's father and her twin brother have enlisted in the Union army, even though her twin, Luke, is only old enough to be a drummer. The two girls become best friends, and then Virginia-born Rosanna goes back to Richmond and her parents. It's almost impossible for the girls to keep in touch, since only smuggled messages can travel between the two sides during the Civil War. But news of Rosanna 's marriage to a man who joined the Confederate army does reach Gettysburg. When Rosanna learns that her husband has been injured in battle, she travels to the Confederate army to nurse him. Both girls get swept up in the affairs of the times, as Lizzie must quit school to manage her father's butcher shop, and Rosanna learns to treat all sorts of battle - related ailments of the men of the Confederate army.
In Two Girls of Gettysburg, Lisa Klein has included much that is historically accurate, including details of the Battle of Gettysburg and Lincoln's trip to deliver his now-famous speech. But what she also does very well is make the reader feel right there in the thick of things, experiencing the hopes and fears of any kid growing up at that time, along with the life-and-death situation of being in the midle of a battleground where people know and love participants on both sides.