What can I say for why Jackie Robinson was influential and how he changed sports and civil rights?
Jackie Robinson was influential because he was the first African American to play in Major League Baseball. Before his debut in 1947, African Americans were not allowed in MLB.
As to how he impacted other sports and society, you will have to sort of infer his impact because it is not as if you can prove that his playing in MLB caused any of the other things to happen. For other sports, you could say that Robinson showed people that blacks were tough enough to play at the highest level and that they could coexist with white players. You could then list the years in which various other sports desegregated (NFL, NBA, college football, college basketball). As to civil rights, you could talk about how the integration of baseball helped to push integration in other areas. You can say that it inspired African Americans to believe that they could break down barriers just as Robinson was doing.