The correct answer is They showed the country that integration could be successful.
Before Jackie Robinson played for the Dodgers, no other African American man had ever played in the MLB (Major League Baseball). At this time, there was a completely seperate league for African American baseball players. However, Branch Rickey (owner of the Dodgers) felt that Jackie was talented enough to play in the MLB. Having Jackie on the team and showing how he could compete and get along with teammates should that the integration of the races was very possible.