By the outbreak of World War I in 1914, the German Social Democratic Party (SPD) was the largest socialist organization anywhere in the world. Its importance within Germany was legendary, with hundreds of thousands of party members (over one hundred thousand in the capital city of Berlin alone) and hundreds of thousands more organized in party-affiliated unions.

The SPD published dozens of newspapers on both the local and national levels and ran its own school for training speakers and activists in the finer points of economic theory and governmental regulations. It received one-third of the popular vote in national elections and its representatives made up one-quarter of delegates in the Reichstag, Germany’s parliament (not in proportion to their electoral strength, because of the privileging of rural districts).

The Social Democrats were the dominant political party within Germany, which prompted other groups to form coalitions in order to thwart social democratic aspirations for the reorganization of society. The SPD was so powerful that it formed, in the words of Gerhard Ritter, “not only a political way-of-life but a social community as well . . . a society within a society, a state within a state.”