What does King mean when he refers to the African American as an "exile in his own land"?

he means that African Americans were separated and they weren't as majority. they weren't seen as citizens. They didn't have the same rights.

the church governed the society after the empire fell.   constantine took charge of rome and ended the confusion which had over religion and made christianity as the only religion and that started ruling the roman empire. he also divided the empire into two and fortified the eastern part.   he ruled the eastern part.