This book is a detailed narrative of Colonel Mason Whiting Tyler's service as a Private and an Officer from his enlistment in July 1862 to his wounding on March 25, 1865. His Regiment was the 37th Massachusetts Volunteer Infantry and he was at Fredericksburg, Chancellorsville, Gettysburg, The Wilderness and Petersburg. He also served under Sheridan in the Valley Campaign and during the Draft Riots he was transferred to New York City to help quell the mayhem there.

His story is told in a continuous autobiographical narrative up to the arrival of his Corps at Petersburg in mid-June of 1864. The rest of it is in the form of excerpts from his diary and letters to family and friends with an explanatory description of the progress of the war by the Reverend Calvin Stebbins heading each chapter for Colonel Tyler died in 1907, before he had finished his manuscript.