Imperial Deputation of the Frankfurt National Assembly on 3 April 1849 (the Prussian king Frederick William IV declines the Imperial status offered to him. "The Imperial deputation from Frankfurt before Frederick William IV" -Steel engraving, 1861, by Veit Froer (born 1828) after a drawing by Rudolf Geißler (1834-1906). Berlin, Sammlung Archiv für Kunst und Geschichte.