It was Jackie Robinson's first time playing in a real stadium. Blacks had been barred from doing certain things, and going certain places, and doing sports. Branch Rickey, his managae, had been first to break that law.
There were many angry fans, all excoriating Jackie. They heavily criticized him, and thought he didn't belong there.
But there were also other people. Black people, children, and even others. They all just wanted to see Jackie play. "Atta boy, Jackie," Screamed a child. That pushed Jackie to win.