Rubuta ci gaba don wannan sakin layi - Komawa Amurka a matsayin kwamandan kwamandan a Watertown Arsenal, ya sake tafiya zuwa Turai a ƙarshen 1914 a matsayin mai lura da sojojin Amurka tare da sojojin Jamus na tsawon watanni shida. Yanzu, mai kula da kwamandan kwamandan, ya sake daukar nauyin aikin tare da Kwamitin Gun Forgings daga Mayu 1915 har zuwa Yuni 1916. Bayan watanni takwas a matsayin jami'in bindiga na Ma'aikatar Kudancin Sojojin a lokacin da aka tattara rundunonin Sojojin Kasa da na Kasa don Kashe Kashe
, an kira shi zuwa Washington a ƙarshen Fabrairu 1917, don zama mataimakin shugaban kayan aiki. Tare da shigar Amurka cikin Yaƙin Duniya na I a watan Afrilu 1917, ya yi tafiya zuwa Faransa a matsayin babban jami'in sojan Amurka. Williams ya shafe watanni goma sha ɗaya a can, a lokacin da ya ci gaba da digiri biyu zuwa matsayin brigadier general.