After attending the Gymnasium (secondary school), Wilhelm Schepmann completed the teacher’s seminar and then worked as a teacher in Hattingen. He served in the First World War from 1914 to 1918 as a soldier of the Westphalian hunter battalion No.7 and was deployed on both the western and eastern fronts. During the war, he was first company commander in the rank of lieutenant of the reserve, then battalion adjutant, and finally court officer.