Final answer:
Branch Rickey wanted to integrate baseball because he believed it would make his team better and increase gate receipts in New York, reflecting a commitment to racial equality and the influence of capitalism on integration decisions.
Step-by-step explanation:
The sentence from "Jackie Robinson: Justice at Last" that best explains why Branch Rickey wanted to integrate baseball is: "Robinson was acquired by the Brooklyn Dodgers by a coach who recognized that integration would make his team better and immediately boost gate receipts in a diverse city such as New York." This sentence highlights the dual incentives for Rickey's decision - improving the team's performance and increasing ticket sales due to the diverse population of New York City. Rickey's commitment to racial equality also played a role, as did the success of Robinson, which inspired other teams to integrate. Additionally, it reflects the influence of capitalism and the prospect of increased financial returns which was a driving force behind the rapid integration after Robinson's debut.