The regiment was then assigned to General Robert E. Lee's Army of Northern Virginia, and soon after attached to the Texas Brigade. Tebbs was promoted to Lieutenant-Colonel following Manning's promotion to colonel in early 1862. He would serve with the regiment in the battles of Cheat Mountain, Seven Pines, Harpers Ferry, Antietam, and Fredericksburg, in addition to several smaller battles and skirmishes in between. In bad health, Tebbs would resign his commission and leave Confederate service on January 11, 1863.