It was only towards the end of the 1815-66 period that a specifically socialist political tendency developed out of the broader radical and democratic movement. If there is any one individual who could be called the founder of a socialist or social-democratic party in Germany it would be the author and political agitator Ferdinand Lassalle (1825-64). In his famous "Open Letter" of 1863, he called for the creation of a socialist labor party. Such a party would not just be socialist, it would also take up the liberal demand for constitutional and parliamentary government and the radical demand for a democratic suffrage because, in Lassalle's opinion, the existing liberal and democratic parties had failed to do so. The labor party would thus become, in effect, the heir to their aspirations.
One of the distinctive aspects of the German political system between 1871 and 1933 was the existence of a specifically Roman Catholic political party in addition to socialist, radical, liberal, and conservative parties. This party enjoyed the strong support of Germany's Catholic population. Before 1866, though, it was unclear if such a party would come into existence. There were certainly church-going, devout Catholics involved in politics; there were Catholic associations and societies active in public life, but the question of whether these societies should be the basis of a Catholic political party, and whether devout Catholics should be politically active in it, was unresolved. During the revolution of 1848, Germany's Catholics formed Pius Associations (named after Pope Pius IX); the general assembly of the Pius Associations of the Rhineland and Westphalia, held in Cologne from April 17-20, 1849, included a revealing debate about whether these associations should just deal with religious questions or should make their opinions known on all political questions – in effect, form a Catholic political party. The chief participants in the debate, Franz Xaver Dieringer (1811-76), Professor of Theology at the University of Bonn, the Cologne attorney Hermann von Fürth (1815-88), Franz Joseph Buß (1803-78), Professor of Law at the University of Freiburg, and Iganz Döllinger (1799-1890), Professor of Theology at the University of Munich, were all prominent Catholic political activists. Their arguments centered on the question of whether a Catholic political party would be good for the Church, but also whether Catholics could best make their influence felt in public life by forming their own party or by working through other, existing political parties.