Zollverein
2 of the 6 encyclopedias on this shelf carry an entry for Zollverein. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
the German commercial or customs union, founded originally in 1827, but extended greatly after the war of 1866, when, owing to political considerations, Prussia obtained a preponderating influence in the union, which included the North German Bund, Bavaria, Württemberg, Baden, Hesse, and Luxemburg. This arrangement was brought prematurely to an end by the formation of the German empire. By article 33 of the constitution of the empire, the territory of the Zollverein coincides with the territories of the empire, with the exceptions of the free ports of Hamburg, Altona, Bremen, Bremerhaven, Geestemünde, and Braahe, and some communes of the grand-duchy of Baden, Baden, while Luxemburg and the Austrian canton of Jungholz are included in it. Its object is the regulation of a uniform rate of customs duties throughout the various states comprised in the union. The free ports were included in the Zollverein in October, 1888. Hence, any commercial or customs union.
Aiton's Encyclopedia (1910)
tsol'fe-rin, a union of North German states, 1818-1871, for the purpose of collecting customs. It was formed by Prussia to escape the many annoying customs collected by the petty states within its bounds. By 1865 nearly all Germany, outside of Austria, was included in the Union. A single set of custom officers collected customs at the outer border of the union, as is the case in the United States . The revenue was divided according to agreement. The Zollverein was supplanted practically by the formation of the German Empire at the conclusion of the Franco-Prussian War . In fact, the empire may be said to have grown, in part at least, out of the customs union.
What Has Changed in the Last Century
Collier's still described a live institution in 1921, listing Luxemburg and the Austrian enclave of Jungholz inside German customs territory — but Luxembourg had already given notice and left the German customs union in 1919, tying itself to Belgium instead in the Belgo-Luxembourg Economic Union of 1921, while Jungholz's anomalous status ended when Austria joined the European Union's customs territory in 1995. The Zollverein itself is now purely historical: the free-port privileges Collier's noted survived in shrunken form until Hamburg's free port was abolished in 2013. Aiton's claim in 1910 that "the empire may be said to have grown, in part at least, out of the customs union" is still argued, though historians today generally treat Prussian political and military power, not tariff policy, as the decisive force in unification. The idea itself outlived the thing: the European Economic Community's customs union, completed in 1968, was repeatedly likened to a Zollverein for the continent.
Written for this edition, 2026.