It's a blend of reality and creative interpretation. The core events and characters have roots in real life, but the story has been shaped to make it more engaging for the audience.
Partly. While it's rooted in some real circumstances and people, there might be some artistic liberties and fictional elements added for dramatic effect.
One Night in Miami is somewhat true. It incorporates real historical figures and events but fictionalizes certain aspects to make it more engaging for the audience.
The main events are more of a speculative nature. It's about the four men coming together. They might have talked about their respective impacts on the black community. For example, Ali's stance against the Vietnam War which was also related to the civil rights struggle. And Sam Cooke's attempts to cross over in the music industry while still maintaining his roots and message.