I talked to a lot more black programmers in meetups in Atlanta than I have in San Francisco (I'm not American and was a visitor in both places) & was surprised by how biased against the former people in the latter were, despite evidence to the contrary.
In Atlanta race is not a special issue, it's a fact of daily life. Interacting with black people isn't an unusual event where you get to pat yourself on the back for 'not being racist'. It's simply what happens everyday.
Or maybe I am just bitter about a 70% white city talking about how racist a 53% black city must be.