This book is an in-depth exploration of the experience of the US Marine Corps during the so-called small wars era, 1915–1934, with an emphasis on the marines’ employment of aviation. The introduction to the book provides a brief history of the Marine Corps up to World War I, an explanation of small wars as a concept, and terms and definitions. The chapters are chronological, addressing the origins of Marine Corps aviation prior to and during American involvement in World War I and the Marine Corps’ interventions in Haiti, the Dominican Republic, northern China, and Nicaragua. The chapters explore the development of tactics, techniques, and procedures in the employment of aircraft during interventional operations; the evolution of aviation technology, including engine technology; and what the marines accomplished, failed to accomplish, and learned about the employment of aviation in combat against guerrillas and other irregulars. The conclusion addresses why it all matters in terms of the present (today, small wars are more commonly referred to as irregular warfare) and the future. The book includes numerous photographs never published before, as well as maps, appendices, and an extensive bibliography.