Blood and Iron

Germany fails to unify in the 1860s, resulting in a far different world than our own.

Background
By 1866 Prussia, under the leadership of Otto von Bismarck, was on its way to unifying the German states. With victory over Denmark, the next obstacle to unification was the Austrian Empire. Accusing Austria of violating the Gastein Convention, Bismarck sent Prussian troops to attack. But here's when history changes. The world rapidly changes without a unified Germany, without blood and iron.
 * 1) Ferdinand Cohen-Blind, a radical, successfully assassinates Bismarck in Berlin as the war begins.
 * 2) The Austrians decisively defeat the Prussians at the Battle of Koniggratz due to a failure in Prussian communications and a successful Austrian cavalry charge.  The Austrians win the war, and the Prussians are humiliated. Austria's military victory keeps their sphere of influence over the German states intact, and Prussia, without its Iron Chancellor, begins to decline.