The Last Full Measure — Ann Rinaldi

As Confederate and Union soldiers take over their town, the local residents can do little more than hunker down in their homes while cannon and gunfire explode around them. But the battles are not only fought between soldiers. At home, fourteen-year-old Tacy and her disabled brother lock horns as David struggles with his desire to go to war. He has strong principles, and it tortures him to allow others to fight while he does nothing.

In the aftermath of this great and terrible battle, in which so many soldiers sacrifice their lives for their beliefs, David gives his last full measure...and leaves Tacy struggling to make sense out of it all.