I have been reading about the Mortara case, in which a young boy was taken from his Jewish family in 1858 because a servant had allegedly baptized him. The law of the Papal States apparently said that this made him irrevocably a Christian, and it was therefore illegal for him to be raised by a non-Christian family.

The Wikipedia article says that the resulting international controversy played a part in the downfall of the Papal States during the unification of Italy, in part because it influenced Napoleon III to change his position. How big a role did this one incident really play, though? For that matter, I don't know much about the Papal States or Italian unification to begin with, so any broader context would be helpful. Thanks in advance!