ZOLL'VEREIN (Ger., "customs-union"), a union of different independent German states, under the leadership of Prussia, so as to enable them, in their commer cial relations with other countries, to act as one state. When, after the war of liberation in 1815, the political union, destroyed by the downfall of "the holy Roman empire," had been restored to a certain degree in the German " bund" (see GERMANY), internal commerce was felt to be trammeled and depressed by the collection of revenue at the frontiers of every petty state; nor was it possible, without united action, to carry out the policy in regard to foreign commerce which might be thought best for protecting and developing the native trade and manufactures. The first suggestion of such a union came from Prussia; but'it took many years before an actual beginning was made, and still longer before it reached its ultimate extent, as the plan was opposed for a long time by the jealousies and special interests of many of the states.
From 1819 to 1828, only some of the minor principalities inclosed within the Prus sian territories had been got to conform to the Prussian commercial system; but in 1828, Hesse-Darmstadt, and in 1831, Hesse-Cassel, gave in. This was followed, in 1833, by the accession of Bavaria, Whrtemberg, the kingdom of Saxony, the principality of the same name, Schwarzburg, and Reuss; and in 1835-36, by that of Baden, Nassau, and Frankfort-on-the-Main. The adhesion of Hanover did not take place till 1851, of Olden burg till 1852. When in 1868 Lubeck and the two duchies of Mecklenburg had joined the zollverein, its territory extended over the whole of what subsequently became the German empire, with the exception of Hamburg, Bremen, and a small part of Baden near Schaffnausen. The reichsland of Alsace-Lorraine was incorporated in 1871. The imperial constitution of April 16, 1871, recognizes and ratifies the privilege of the free ports so to remain until "they themselves demand admittance within the coin mon customs-boundary."
The principle of the Zollverein's action was this: The whole territory embraced by the union formed commercially (in regard, at least, to countries beyond its limits) one state. The duties on exports, imports, and through transports were collected at all the frontiers of the union a uniform tariff (subject to some concessions, made on special grounds, to individual states); and the proceeds, after paying the expenses of collection, were divided among the members of the union in proportion to their several populations. In regard to the internal trade of the union, as the duties on articles manufactured for home consumption were different in the different states, a complicated system of drawbacks came into play, in order to put the commerce of all on an equal footing, The treaty of union was agreed upon for a definite period of years, and was renewed from time to time; as in 1842, 1853, 1865, 1867. In the latter year much was done to simplify the relations of the various states to one another in respect of internal trade; and the administration of the Zollverein was so modified as to give to the various mem bers of the union votes in its council and parliament proportionate to the number of inhabitants in each state.
Since the establishment of the German empire, the Zoliverein has no longer a separate constitution of its own. Its council (representing,governments)is merged in the federal council of the empire; its parliament (representing populations) in the reichstag. Affairs are managed on the principles adopted by the Zollverein in 1867, by permanent committees of the federal council—viz., those for customs and taxes, for trade and commerce, and for finance.
The net income of the Zollverein, which, in 1834, amounted only to 12,178,761 thalers, had risen in 1871, the last year in which the Zoliverein had separate accounts, to 28,000,002 thalers (above 14,000,000).