The Marine Corps heritage extends beyond its formal history to encompass its traditions and culture. Like the previous two volumes, this volume is about the junior officers and enlisted Marines who provide the bulk of that heritage. This volume continues the stories of World War I Marine Corps heroes that began in Volume IV, Marine Corps Heroes 1918 Toulon and Belleau Wood . It covers the battles of the Fourth Marine Brigade in the Aisne-Marne (Soissons) and St. Mihiel offensives. Unlike the previous volume, which covered the five-week Battle for Belleau Wood, 1-26 June 1918, this volume covers two multi-division offensive operations spanning just four days of actual combat: 18-19 July in the Aisne-Marne (Soissons) offensive, and 14-15 September in the St. Mihiel offensive. The Fourth Brigade entered the Battle of Belleau Wood relatively untested in actual combat against a modern European army. In contrast, the Fourth Brigade entered the Soissons operation with recent combat experience and battle-tested leadership. The failures occurred at higher echelons of command, where the concept of combined arms operations was only beginning to emerge. In the St. Mihiel Salient, the Brigade tested the American doctrine of open warfare and experienced tactical and operational success that left the Fourth Brigade stronger, more cohesive, and combat effective. Some of the 65 Marine heroes in this volume are mentioned in standard Marine history books for their heroic actions in combat, but no historian has written the full stories of their military service. Major (and former Gunnery Sergeant) Louis Cukela, a Serbian-born recipient of Army and Navy Medals of Honor, was one of the most colorful and controversial Marines of all time. Colonel John W. Thomason Jr. became famous for his self-illustrated short stories that captured the color and flavor of the “Old Corps.” Major Generals Ralph S. Keyser and L.W.T Waller Jr. both achieved their rank following nontraditional career paths. However, most Marines in this volume were “ordinary” and long-forgotten men who performed extraordinary acts of heroism in the Soissons and St. Mihiel offensives.