European nationalism, in its modern sense, was born out of the desire of a community to assert its unity and independence. In the 19th century there began a determined struggle to realise nationalist aspirations. ... It spread the ideas of liberty, equality and fraternity and generated the spirit of nationalism.
This time was referred to as the "age of natioalaties" New nation-states form all around the world. This is why divisions that merged in the U.S. were noticed as nationalism.
