This book chronicles the career of the Regular U.S. Infantry troops who fought in the eastern theater of the Civil War. Despite regional prejudice, recruitment difficulties, and ghastly casualties, the Regular Division formed the backbone of the Army of the Potomac, setting an enviable example for the volunteer regiments. Under the command of General George Sykes, the division figured prominently in the battles of Gaines' Mill, Second Manassas, Gettysburg, and the Wilderness. At Gettysburg half their number were casualties. By 1864, the division had been fought to near extinction, prompting their removal from the field. As professionals, their service spanned the years both before and following the war, but never received the level of recognition comparable to that of the volunteer army. Appendices include tables of regimental representation by companies stating when each joined or left the division; orders of battle by companies for each engagement; Medals of Honor awarded; classification of officers; Roll of Honor; and regimental casualties by engagement.