The German constitution provided for a two-house parliament. Members of one house, the Reichstag, were elected by the people. Members of the other house, the Bundesrat, were appointed by the state governments. The empire had 26 member states. Most states were small, and several were completely surrounded by Prussia. The emperor, who was also the king of Prussia, controlled foreign policy, commanded the army, and appointed the chancellor. The parliament approved all laws and taxes, but could not force the chancellor to resign.

Bismarck allowed all men over 25 to vote, thinking that most Germans would support the government. He won support from the growing class of business people and the traditional Prussian landowners and nobles. But Bismarck faced opposition from Roman Catholics and Socialists. Catholics did not trust the Protestant-led empire and organized their own political party. Socialism was growing popular among city dwellers and the workers in the developing industries. Bismarck tried to wreck the Catholic and Socialist parties, but failed.