This is one incredible book! I would compare it to "The Beantown Girls" by Jane Healy, as it centered around the Red Cross Clubmobiles during WWII.
This book revolves around three women who are sending their husbands, brothers, and friends off to war. These women want to make a contribution to the war effort too, besides working the family farm or in an airplane engine plant. They develop a bond/friendship that surpasses old age and is stronger than any that they have ever experienced before. Ruth is a young wife, teacher, and makes the critical decision of becoming a member of the Red Cross Clubmobile women. There is Lilly, who is Ruth's sister-in-law, and Helen, a British war bride that comes to America for safety from the war and its' battles.
All Clubmobile members are women, have to pass a battery of tests administered in Washington D.C., and if accepted, go the front lines to support the troops by serving doughnuts, coffee, gum, music played on a victrola, and listening to the soldiers so as to boost their morale. They learn how the big trucks they are traveling in work, how to fix and drive them, and even sleep in them at times. They are found to be vital to the soldiers mental health, and very much appreciated.
The book is unusual in that it tells the story by using different characters in each chapter. Sometimes there are letters to read. Personalities come into play. I couldn't put it down.