sentence: union forces at shiloh abbreviations used military rank mg = major general bg = brigadier general col = colonel ltc = lieutenant colonel maj = major cpt = captain lt = lieutenant artillery 3 '' r = inch caliber ordnance rifle how = howitzer lb = pound ( projectile weight ) nap = m1857 napoleon gun r = rifled gun sb = smoothbore gun other w = wounded mw = mortally wounded k = killed c = captured army of the tennessee mg ulysses s. grant , commanding general staff & headquarters chief of staff : col joseph d. webster chief of engineers : col james b. mcpherson assistant adjutant general : cpt .