What led to the unification of Italy and germany? How were both states formed

Well, for Germany, Otto von Bismarck, a decorated war-hero, appealed to national feelings through three wars: Danish War, 7 Weeks War, and Franco-Prussian War. Bismarck won all of the three wars, and this led to the creation of the German Empire.

For Italy, Count Cavour of Piedmont-Sardinia, he unified northern Italy with a war against Austria. Then he invaded the South and unified it too. Rome and the Papal States joined after France was too busy fighting in the Franco-Prussian War.