|WWI Service Record of Carmine Lanzillotta, NYS Archives|
Carmine Lanzillotto fought in the Battle of the Argonne Forest, officially known as the Meuse-Argonne Offensive; it's both the only engagement listed here, and the only battle my grandmother had ever heard him speak of. He was inducted on 25 June 1918 and was overseas by 3 August 1918. The battle lasted from 26 September 1918 until 11 November 1918, the date of the Armistice that ended the war. Charlie, though, remained overseas until the following September, and was discharged on 6 October 1919.
I'm not sure of all of the abbreviations used in the section "Organizations served in," but "MP" shows up a lot, which accords with the image below, showing Charlie Lanzillotto in his uniform and wearing an "MP" band on his arm.