A fine original Pre-WWII (1936) German tinnie here. Working pin and catch to the reverse. Stamped construction.

On March 7, 1936, German troops remilitarized the Rhineland in violation of the Versailles and Locarno treaties. To legitimize the action, Adolf Hitler dissolved the Reichstag and called for a referendum/election on March 29, 1936. On March 28—the eve of the vote—Hitler gave a major campaign speech aboard the ocean liner Deutschland anchored on the Rhine in Cologne (Köln). This badge was issued to commemorate that rally and the broader remilitarization campaign.