ADAV (Germany): Allgemeiner Deutscher Arbeiterverein

https://en.wikipedia.org/wiki/General_German_Workers%27_Association

The General German Workers' Association (German: Allgemeiner Deutscher Arbeiter-Verein, ADAV) was a German political party founded on 23 May 1863 in Leipzig, Kingdom of Saxony by Ferdinand Lassalle. It was the first organized mass working-class party in European history.[1]

The organization existed by this name until 1875, when it combined with the Social Democratic Workers' Party of Germany (SDAP) to form the Socialist Workers' Party of Germany. This unified organization was renamed soon thereafter the Social Democratic Party of Germany (SPD), which presently remains in existence and dates its origins to the founding of the ADAV. Its Austrian part would become the SPÖ.

The ADAV was the first German Labour Party, formed in Prussia prior to the establishment of the German Empire. It was active in the German Confederation, which included the Austrian Empire.[2]