Zollverein (tsôl´fərīn´) [Ger.,=customs union], in German history, a customs union established to eliminate tariff barriers. Friedrich List first popularized the idea of a combination to abolish the customs barriers that were inhibiting trade among the numerous states of the German Confederation. In 1818, Prussia abolished internal customs and formed a North German Zollverein, which in 1834 became the German Zollverein after merging with two similar unions, the South German Zollverein and the Central German Trade Union, both founded in 1828. Customs barriers of member states were leveled, and a uniform tariff was instituted against non-members. The customs at foreign frontiers were collected on joint account, and the proceeds were distributed in proportion to the population and resources of the member states. A rival customs union, the Steuerverein of central Germany, was also organized in 1834. A series of treaties (1851–54) joined it to the Zollverein, which then comprised nearly all the German states except Austria, the two Mecklenburgs, and the Hanseatic towns. Prussia, despite the insistence of several states, was unwilling to admit Austria to the union, but the two countries negotiated a separate tariff treaty. After the Austro-Prussian War (1866) a new agreement was reached by the members of the union. The newly formed North German Confederation entered the Zollverein in a body, and the other German states also negotiated customs treaties with victorious Prussia. The constitution (1867) of the new Zollverein provided for a federal council of customs (Zollbundesrat), comprised of personal representatives of the several rulers, and for an elected customs parliament (Zollparlament). In both bodies Prussia exercised predominant influence. In 1871 the laws and regulations of the Zollverein passed into the legislation of the newly created German Empire. Alsace-Lorraine entered the imperial customs area in 1872, and the Hanseatic cities joined in 1888. The Zollverein promoted the economic unification of Germany.
See studies by J. R. MacDonald (1903, repr. 1972), W. O. Henderson (2d ed. 1959), and E. N. Roussakis (1968).