In answer to the first question events that led to the unification of Germany included: .
The defeat of Napoleon brought the beginnings of the Congress of Vienna. The congress was called in order to the restore balance of power in Europe and to ensure France could never expand out side of its original pre-war boundaries.
The countries that were involved in the battle of Leipzig (Russia, Prussia, Britain and Austria) were main players in the congress. Land that was part of the French Empire was doled out to each major power to ensure no power became too large. The Congress also created the German Confederation. After the Congress of Vienna, four Major players began the first European Council which would try and keep peace in Europe.
CONSERVATISM AND THE REVOLUTION OF 1848:.
In the period after the Congress of Vienna, liberal ideas based on Napoleon's rule were "squelched" under the Metternich system, a conservative, reactionary system. The Conservatives discouraged any movement to unify Germany and the over bearing policy of the Metternich system initially put down liberal ideas. In German states, violent uprisings of peasants and liberals began, sparked by strong desire for reform. Princes from individual states, unaware of what occurred, granted parliaments and constitutions to the people, appointing liberal ministries and ending feudal dues.
Liberal revolutionaries created the National Assembly whose goal was to unify Germany as a liberal, constitutional state. In May 1848, the National Assembly was called to prepare for this "unification". After disagreements between Prussia and Austria, Prussia tried to unify Germany under their kliendeutsch plan. In 1848, the Assembly finished the constitution, appointed King Frederick William as the first emperor of Constitutional Germany. Frederick immediately cancelled the Constitution and declared his divine right to rule. While the princes cancelled the concessions made to the liberals in 1848-49, the armies of the monarchy quickly crushed the liberal movement in South Germany thus centralizing power.