 Pari gbolohun ti o tẹle: Awọn adehun ti Awọn Agbara Iṣilọ Amẹrika ni Ilu Faranse Gbogbogbo John J. Pershing, olori ninu eyiti o kopa pẹlu : St. Mihiel 12-21 September 1918, trench and tank combat against German defensive positions in northeast France, hampered by driving rain, mounting mud, and overstretched supply lines; Meuse-Argonne 26 September 1918  11 November 1918 frontal assaults village to village on the Western Front and through the Argonne Forest; and, post-Armistice, the general defense duty recognized as Defensive Sector. ì ì ì Fún iṣẹ ìsìn rẹ, Rennie gba àmì ẹyẹ Victory Medal with Service Clasps. Kódà nígbà tí Rennie wà lẹnu iṣẹ ológun pàápàá, kò fi bẹẹ nífẹẹ sí ìwé kíkọ. Awọn iwe iroyin akoko ogun rẹ ni awọn itọkasi lọpọlọpọ si ibẹrẹ iṣẹ oniroyin ominira, pẹlu awọn ifiranṣẹ ti awọn ewi, awọn itan kukuru, ati awọn nkan si awọn iwe irohin ati awọn iwe iroyin. Lẹyìn tí Rennie padà sí Orílẹ-Èdè Amẹríkà ní May 1919, wọn dá a sílẹ lọnà tó buyì kún un. 