September 9, 1918: Six-horse artillery caissons of the U.S. 1st Infantry Division, “The Big Red One,” moving up through the woods in Mandres aux Tours (Mandres-aux-Quatre-Tours?), in north-east France’s Lorraine region. The guns should be famed “French 75s” (Canon de 75 modèle 1897) of which the American Expeditionary Forces used some 1,900 during 1917-18, dubbed the more GI “75 mm Gun M1897.”

Note the consistency of the horse’s coats and the doughboys smoking cigarettes as they ride. Photo via the Society of the First Infantry Division
However, a 1936 Christmas Card for the veterans of the 1st ID’s 76th Field Artillery Regiment, signed by John J. Waterman, Lieutenant Colonel, reads:
Battery B moving through the woods, Mandres aux Tours, France, August 9, 1918.
A copy of this picture enlarged by two by three feet hung in the office of the Chief of Field Artillery. The regiment spent a little over two weeks at Mandres, re-equipping, and training for the St. Michel offensive.
Of note, the commander of the regiment’s Battery D should be familiar to students of military history.