Complex sentence: In the early 1960s, Birmingham was one of the most racially divided cities in the United States, as black citizens faced legal and economic disparities as well as violent retribution when they attempted to bring attention to their problems.
Split into simpler sentences: In the early 1960s, Birmingham was one of the most racially divided cities in the United States. Black citizens faced legal and economic disparities, and violent retribution when they attempted to bring attention to their problems.