Dietrich Bonhoeffer was able to observe the racism that whites had towards blacks when he was in America 1930-1931. He wrote:

The separation of whites from blacks in the southern states really does make a rather shameful impression. In railways that separation extends to even the tiniest details. I found that the cars of the negroes generally look cleaner than the others. It also pleased me when the whites had to crowd into their railway cars while only a single person was sitting in the entire railway car for negroes.      

(Bonhoeffer, Pastor, Martyr, Prophet, Spy by Eric Metaxas, 114).