Mainz has helped shape the history of Germany, and even Europe, throughout many periods of the city's history. The democratic tradition here has its roots in the late 18th century. Its history is also closely linked to the history of democracy in France. The French Revolution in 1789 paved the way for the establishment of the "Rhenish-German National Convention" in 1793, the first democratically constituted parliament in Germany, which met in the Deutschhaus.

Along with the Deutschhaus—now the seat of the Rhineland-Palatinate State Parliament—the Dalberger Hof is one of the six sites in Mainz. It was the site of a high treason trial from May 23 to June 8, 1850, in which 77 democrats from Mainz and Rheinhessen—who had participated in the Palatinate uprising in 1849 as members of the Freischärler militia—stood trial. In 1887, the “Mainz Secret Society Trial” was held there against eight Social Democrats for violations of Bismarck’s Anti-Socialist Law.

In 1848, the State Theater was the scene of popular gatherings during the March Revolution. The citizens' militia set up its headquarters in the left wing of the theater. Citizens had previously announced their March demands, including freedom of the press, in the square.

In the period leading up to the March Revolution, the Frankfurter Hof was the place where the political and literary carnival developed. The topics of the meetings were censorship in the printing industry and German particularism.

Starting in 1848/49, the Iron Tower served as a prison for those democrats from Mainz and Rheinhessen who had been put on trial at the Dalberger Hof.

It is said to have been a rather lenient prison: on occasion, prisoners were reportedly replaced overnight by visitors.

The high treason trial against them ended in June 1850 with the acquittal of all the defendants, who were greeted by a cheering crowd upon their release.

The Main Cemetery commemorates the events of 1848 in Mainz with the so-called Prussian Monument. Here, Prussian soldiers remember their comrades who fell in street fighting on May 21. Convinced democrats such as Dr. Eduard David, Bernhard Adelung, and Dr. Dr. h.c. Emil Kraus also have their final resting place in the cemetery.