The book "History of Troop A Cavalry, Connecticut National Guard and its service in the Great War as Company D, 102nd Machine Gun Battalion" tells about the distinguished military past of the American unit, which preserved and passed on the heroic legacy of the participants of the First World War. The author examines in detail the military events, strategic decisions, and exceptional bravery of the soldiers who made up the history of Troop A Cavalry during military operations, as well as their service as part of the 102nd Machine Gun Battalion. This book will become an indispensable source of knowledge for anyone interested in military history and the actions of unspeakably brave and loyal soldiers.