Final answer:
The ideology present in Wilhelm I's proclamation is nationalism, as it promotes the unity of German states under a single imperial title and evokes a sense of national pride.
Step-by-step explanation:
The ideology present in the proclamation of Wilhelm I is nationalism. This is evident in his emphasis on unifying the German principalities under a common imperial title and his appeal to the glory of the fatherland. The proclamation reflects the spirit of national unity and the desire to establish a strong, unified German state that emerged after the victory over France, and was championed by influential figures like Otto von Bismarck, who employed Realpolitik for the practical consolidation of German territories under Prussian leadership. The proclamation does not adhere to the ideologies of communism, absolutism, or imperialism, which are associated respectively with the advocacy of class struggle and the common ownership of property, the absolute rule of a monarch, and the extension of a nation's power via the acquisition of territories overseas.