You have to start looking a little bit further back to really get the answer.
Way back in 1850, when the slavery debate first started, President Zachary Taylor fought to ensure that the Western States (California, in particular) were admitted as free-states. Shortly after winning that debate, he died. (I think of a stomach infection from bad milk. The Wiki article will say.) Leading up to the period in question, there were actually very few black people in the west than elsewhere. (Remember- African-Americans were initially brought into the country for the sole purpose of being slaves and it was rare that they ever moved away from the South.) Out of those, there were few that had much opportunity or who were academics. They were definitely treated better in the west than in the south, but the Northeast was probably the best place to be in a minority, because that was where there were schools building up for them there and a little more opporunity.
So, the North>West>South is the best way to write this out, I think. The few blacks in the west were treated well, but didn't have as much opportunity as those in the Northeast.