Tuhia he tomokanga mō tēnei wāhanga - I te tomokanga o te Hononga o Amerika ki te Pakanga Tuatahi o te Ao, i te Paenga-whāwhā 1917, i whakawhiwhia a Middleton ki te 4th Infantry Division, a, i kite wawe ia i te mahi hei kaihautū patereona i te Pakanga Tuarua o te Marne
He aha? E toru marama i muri mai, whai muri i etahi mahi tautoko iti, i arahi tana roopu i te whakaeke i te Meuse-Argonne Offensive, a ka noho a Middleton hei rangatira rangatira. Na tana mahi whakahirahira i te pakanga, i te 14 o Oketopa 1918 i whakatairangahia ia ki te taumata o te koronel, ka noho, i te 29 o ona tau, ko te rangatira taitamariki o taua taumata i roto i te American Expeditionary Force (AEF). I whakawhiwhia hoki ia ki te Tohu Ratonga Motuhake mo tana mahi tauira. Whai muri i te Pakanga Tuatahi o te Ao, i mahi a Middleton i te US Army School of Infantry, te US Army Command and General Staff School, te US Army War College, me te rangatira o nga kaiako i LSU. I reti ia mai i te ope taua i te 1937 ki te noho hei rangatira mo te whakahaere me te kaitohutohu me te perehitini tuarua i LSU. Ko tana noho ki LSU he uaua, i te mea ko Middleton tetahi o nga kaitakaro nui ki te awhina i te whare wananga ki te whakaora mai i te raru nui i ngaro ai te tata ki te miriona taara.