The Treaty of Versailles of June 1919 forced the Wagner family to leave Alsace and to move to Urberach in southern Hesse.
From 1921 to 1923 Wagner studied at the Städelschule in Frankfurt am Main with Friedrich Christoph Hausmann and Johann Vincenz Cissarz.
For the Sprinkenhof in Hamburg, designed by Höger, Wagner created four large sandstone sculptures; two of which were destroyed by bombs in 1943.
Through the construction projects of his brother Ferdinand he received many public and private commissions in the entire Frankfurt area.
During the last years before his death, however, he only dealt with drawings, paintings, small sculptures and reliefs, most of which remained in his family's possession.