Edited sentence: As one historian has concisely noted: "Once the integretative or leveling model of baseball -- all America playing and working in harmony -- was extended to African Americans, the effect on the nation was profound.Eighty years after the Civil War, America had proved itself unable to practice the values for which it was fought.Jackie Robinson's remarkable courage, as expemplified by his early protest in the military long before his entry into a very popular and public sport, and his resolute stand for simple human decency must therefore be seen as profoundly important not only to professional sports, but to the entirety of American culture.Jackie's life, including the military court martial which cleared his name of insubordination for refusing to submit to the humiliation of segregation, may thus be seen as an early turning point in the life of the nation.The racism which poisoned baseball permeated all of American society