What is the act of separating from a nation and becoming independent?

The act of separating from a nation and becoming independent is called secession or declaration of independence.

Explanation:

According to https://en.wikipedia.org/wiki/Secession, secession or declaration of independence is the withdrawal of a group from a larger entity, especially a political entity.

It is a process that begins when a group proclains the act of secession or declaration of independence; it may be a peaceful or violent movement, but its outcome is a new political entity, totally independent.

martin luther king (1929-1968) was an activist for the african american rights, mr. king has a profile of a kind leader that built a tenacity, respect and full of hope future. he was an activist through civil disobedience and no violence pressure mechanisms. he tried to build a more egalitarian and fair society. his efforts carried a reivindication message of the civilian rights to every west corners. for that reason, he won the nobel prize in 1964.

the roman empire began to fall