Was doing some web searching and found this:
Book: Fred Ray’s Shock Troops of the Confederacy: The Sharpshooter Battalions of the Army of Northern Virginia (CFS Press, 2006)
Text: “ While this was going on, the Confederates of Waggaman’s Louisiana Brigade made an attack on Fort Haskell to the south, their sharpshooters out front. “
This text is found in Chap 20 of the book - Attack at Fort Steadman
Based upon what has transpired on this thread, I must stand corrected, there appear to have been sharpshooters in or at least supporting the Louisiana Brigade at a variety of combat actions, at least the 1st Brigade, and the Consolidated Brigade.