When Jackie Robinson finally joins the Brooklyn Dodgers, how do his teammates react

there probably very shocked and surprised

When he joined the Brooklyn Dodgers, his teammates were angry, some even signing a petition demanding to be traded to another team.

Explanation:

Jackie Robinson: Justice at last by Geoffrey C. Ward and Ken Burns narrates the story and resilience of the first black baseball player to play in the major league. Jackie Robinson represents blacks and also open a big door of possibility for the blacks and whites to play together. He signed with the Dodgers in 1946 and began playing in the minors. But not without any consequence. Players insulted him in the field, some of his own players even signed a petition, demanding to be traded to another team.