the Zollverein caused much dissatisfaction and a ministerial crisis. However, the treaty was ratified by the legislature in 1852. This treaty was signed only by Prussia and Hanover. Prussia had not consulted any member of the Zollverein and Hanover had not consulted Oldenburg or Schaumburg-Lippe, who were both forced to follow Hanover into the Zollverein. By an agreement between Hanover and Schaumburg-Lippe on 25 September 1851, the latter adhered to the arrangements in the Prussia-Hanover treaty. Oldenburg acceded by means of a treaty with Hanover and Prussia (jointly) dated 1 March 1, 1852. Both the Zollverein and Steuerverein treaties were due to expire in 1853, which provided the opportunity to negotiate new terms. Notes References Henderson, William. The Zollverein. Publ Cambridge University Press, 1939 19th century in Germany Kingdom of Hanover Customs unions