Nationalism is a unifying effect when it comes to history. Areas with similar languages and values have a lot to say, when you see that much is similar you realize that it is often better together. In Germany, the pus factor was Prussia's expansionism that might start it. This is similar to Italy, where several people speak the same language and share the same values.
The surge of German nationalism, stimulated by the experience of Germans in the Napoleonic period, the development of a German cultural and artistic identity, and improved transportation through the region, moved Germany toward unification in the 19th century.
Other Factors For Unification
By the early 19th century, German roads had deteriorated to an appalling extent. Travelers both foreign and local complained bitterly about the state of the Heerstraßen, the military roads previously maintained for the ease of moving troops. As German states ceased to be a military crossroads, however, the roads improved; the length of hard-surfaced roads in Prussia increased from 3,800 kilometers (2,400 mi) in 1816 to 16,600 kilometers (10,300 mi) in 1852. By 1835, Heinrich von Gagern wrote that roads were the “veins and arteries of the body politic…” and predicted that they would promote freedom, independence, and prosperity. As people moved around, they came into contact with others on trains, at hotels, in restaurants, and for some, at fashionable resorts such as the spa in Baden-Baden. Water transportation also improved.
As important as these improvements were, they could not compete with the impact of the railway. Historians of the Second Empire later regarded the railways as the first indicator of a unified state; the patriotic novelist, Wilhelm Raabe, wrote: “The German empire was founded with the construction of the first railway…” Rail travel changed how cities looked and how people traveled. Its impact reached throughout the social order, affecting everyone from the highest-born to the lowest. Although some of the outlying German provinces were not serviced by rail until the 1890s, the majority of the population, manufacturing centers, and production centers were linked to the rail network by 1865.
As travel became easier, faster, and less expensive, Germans started to see unity in factors other than language. The Brothers Grimm, who compiled a massive dictionary known as The Grimm, also assembled a compendium of folk tales and fables that highlighted the storytelling parallels between different regions. Karl Baedeker wrote guidebooks to different cities and regions of Central Europe, indicating places to stay, sites to visit, and giving a short history of castles, battlefields, famous buildings, and famous people. His guides also included distances, roads to avoid, and hiking paths to follow.
The words of August Heinrich Hoffmann von Fallersleben expressed not only the linguistic unity of the German people but also their geographic unity. Patriotic songs as “Die Wacht am Rhein” (“The Watch on the Rhine”) by Max Schneckenburger began to focus attention on geographic space, not limiting “German-ness” to a common language. Schneckenburger wrote “The Watch on the Rhine” in a specific patriotic response to French assertions that the Rhine was France’s “natural” eastern boundary.
I think the last part will help you the most
