Original sentence: The 19th has had no official history published.The Battalion saw its first action at Saint-Eloi in April 1916 and went on to serve on the Somme, at Courcelette, Vimy Ridge, Hill 70, Passchendaele, Drocourt-Quéant, and the Pursuit to Mons
Edited sentence: The 19th, unfortunately, still awaits its historian.The Battalion saw its first action at Saint-Eloi in April 1916 and went on to distinguish itself on the Somme, at Courcelette, Vimy Ridge, Hill 70, Passchendaele, Drocourt-Quéant, and the Pursuit to Mons