Originating from Troop I of the Buffalo 1st Cavalry (other troops having gone on to form the 104th and 106th Machine Gun Battalions), the 102nd Trench Mortar Battery was mustered into Federal service in June of 1916 for the Mexican Punitive Expedition. It served under the 52nd Artillery Brigade within the 27th Division.

After America's entrance in World War I, when the majority of the 27th Division departed for France, the 102nd Trench Mortar Battery along with the rest of the 52nd Artillery Brigade was delayed at Newport News, Virginia. Upon arrival in Europe, the Brigade trained for another six weeks at Camp Bar-le-Duc near Bordeaux, and was then attached to the 33rd Division, which was serving under the French XVII corps.

In early September, 1918, the 52nd Field Artillery Brigade, with the 102nd Trench Mortar Battery, took up positions opposite the German lines with the 33rd Division near Nixeville, southwest of Verdun. Soldiers observed that, “As a result of this fighting, the country was completely devastated, the villages were destroyed by shell fire and the inhabitants had fled. There was nothing but destruction and desolation.” (O'Ryan, The Story of the 27th Division, 445)

On June 12, 1918, the 52nd Artillery participated in the St. Mihiel Offensive, reducing the German salient. Following the Allied advance, the 52nd Artillery helped drive the Germans northwest of Verdun back across the Meuse River on September 26. The 102nd Trench Mortar Battery, however, was kept in reserve because the width of no-man’s-land exceeded the range of its guns.

On October 15, covered by supporting fire from the 2nd Battalion, the 102nd Trench Mortar Battery built new gun emplacements across the river from Sivry-sur-Meuse. On the night of October 19-20, the 102nd Trench Mortar Battery shelled Vilosnes to assist an attack by the 29th Division; this was the only direct action the 102nd Trench Mortar Battery saw. However, men from the battalion played a valuable role by helping to resupply other frontline positions of the 52nd Artillery Brigade throughout the campaign.