Gates, T. B. (1879). The "Ulster guard" (20th N.Y. State militia) and the War of the Rebellion: Embracing a history of the early organization of the regiments its three months service...complete roster, etc ...its reorganization and subsequent services... together with a brief treatise upon the origin and growth of secession,; the militis system, and the dependence of the federal government upon it in the beginning of the war ; with a critical history of the first batle of Bull Run ; campaign of Gen. Pope ; McClellan's Maryland campaign ; battle of Frederickburg : Hooker's Chancellorsville campaign : Gettysburg campaign ; and a glance at the campaign from the Rapidan to Appomattaz Court House. New York: B.H. Tyrrel, printer.

Gates, Theodore Burr. The "Ulster Guard" (20th N.Y. State Militia) and the War of the Rebellion: Embracing a History of the Early Organization of the Regiments Its Three Months Service...complete Roster, Etc ...its Reorganization and Subsequent Services... Together With a Brief Treatise Upon the Origin and Growth of Secession,; the Militis System, and the Dependence of the Federal Government Upon It in the Beginning of the War ; With a Critical History of the First Batle of Bull Run ; Campaign of Gen. Pope ; McClellan's Maryland Campaign ; Battle of Frederickburg : Hooker's Chancellorsville Campaign : Gettysburg Campaign ; and a Glance At the Campaign From the Rapidan to Appomattaz Court House. New York: B.H. Tyrrel, printer, 1879.

Gates, Theodore Burr. The "Ulster Guard" (20th N.Y. State Militia) and the War of the Rebellion: Embracing a History of the Early Organization of the Regiments Its Three Months Service...complete Roster, Etc ...its Reorganization and Subsequent Services... Together With a Brief Treatise Upon the Origin and Growth of Secession,; the Militis System, and the Dependence of the Federal Government Upon It in the Beginning of the War ; With a Critical History of the First Batle of Bull Run ; Campaign of Gen. Pope ; McClellan's Maryland Campaign ; Battle of Frederickburg : Hooker's Chancellorsville Campaign : Gettysburg Campaign ; and a Glance At the Campaign From the Rapidan to Appomattaz Court House. New York: B.H. Tyrrel, printer, 1879.