Differentiate the following concepts Nationalism, Nations and States​

A nation is a group of people who see themselves as a cohesive and coherent unit based on shared cultural or historical criteria. Nations are socially constructed units, not given by nature. ... A Nation-State is the idea of a homogenous nation governed by its own sovereign state—where each state contains one nation.Nationalism is a feeling of oneness amongst all people residing in the nation

sorry but your romanian isn't clear could you just translate to english

explanation:

the historians cited in the article all agree with one another about the cause of the civil war. despite coming from different backgrounds and cultures, the historians agree that slavery was the root cause of the civil war. the fact that all these historiansgenerally agree with one another makes their shared viewpoints more reliable and valid, especially because the historians have different backgrounds and all work for the well-respected institutions of howard university, clemson university, and the university of colorado.