The constitution was signed by William I, the King of Prussia, acting in his capacity as Bundespräsidium of the North German Confederation, the Kings of Bavaria, Saxony and Württemberg, and the Grand Dukes of Baden and Hesse.
The member states of the North German Confederation that now became members of the Empire were Prussia, Mecklenburg-Schwerin, Saxe-Weimar-Eisenach, Mecklenburg-Strelitz, Oldenburg, Brunswick, Saxe-Meiningen, Saxe-Altenburg, Saxe-Coburg-Gotha, Anhalt, Schwarzburg-Rudolstadt, Schwarzburg-Sondershausen, Waldeck, Reuss (older line), Reuss (younger line), Schaumburg-Lippe, Lippe, Lübeck, Bremen, and Hamburg.