Prussia's dominance in the 1871 German Empire wasn't accidental—it was built on a century of structural advantages that Otto von Bismarck masterfully leveraged.
The Prussian Army, reformed by Scharnhorst/Gneisenau (post-1806) and later Roon/Moltke, introduced the general staff system, universal conscription, needle gun, and railroad mobilization. Victories in 1864 (Denmark), 1866 (Austria), 1870–71 (France) proved its superiority.
The Zollverein (Customs Union, 1834) gave Prussia economic hegemony over northern Germany. The Ruhr and Saar coal/iron fueled rapid industrialization (Krupp, Borsig, Siemens). By 1870, Prussia produced most of Germany's coal, steel, and rail equipment.
The "Iron Chancellor" orchestrated unification through Realpolitik: wars, alliances, and the 1867 North German Confederation constitution (which became the 1871 Imperial Constitution). Prussia held the presidency, controlled the Bundesrat, and commanded the army.
Prussia comprised ~60% of the Empire's territory and population. Its 24M people (of 41M total) and landmass stretching from the Rhine to Russia made it the geographic core.
A meritocratic bureaucracy, professional judiciary, and standardized education (Humboldt model) created state capacity other German states lacked.
Prussian values—discipline, duty, obedience, Protestant work ethic—became the template for "German" identity, reinforced by the university system and officer corps.
Prussia didn't just join Germany; it was the engine that built it, and the Empire was essentially a Prussian-led federation.