 He returned to spend three years in his father's business, before setting up his own practice.Like his father, Dielmann was a leading Catholic layman, as a member of the St. Joseph's Society of St. Joseph's R.C.Church, the Knights of Columbus, Order of Alhambra, San Antonio Liederkranz, the Beethoven Männerchor, and as president of the Harmonia Lodge of the Sons of Hermann.