There was no statute officially banning blacks from baseball, only a universally recognized unwritten rule which no club owner was prepared to break that was perpetuated by culturally entrenched racism and a desire by club owners to be perceived as representing the values and beliefs of everyday American white men. The service of black Americans in the Second World War, and the celebrated pre-war achievements of black athletes in American sports, such as Joe Louis in boxing and Jesse Owens in track, helped pave the way for the cultural shift necessary to break the barrier.