Why had Mr.Morrison lost his job?

Mr. Morrison has lost his job and also needs to get away from the area of the fight lest the whites lynch him for beating them up. It's a good trade: Morrison gets a home and employment (not much pay beyond food and shelter, but that's plenty), and the Logans get someone to keep them safe while David is away working.

Mr.Morrison had a fight with white people but he was the only one fired becuase of his race.

Mr.Morrison had a fight with white people and lost it job because he was black