How do we get a lot of blacks into California, Oregon and Washington? Maybe the black population of the South can see how the South is going to treat them after Reconstruction so they decide to homestead the Great Plains and the West to escape disenfranchisement? What are likely to be the effects of this migration and the development of wealthy blacks in the late 1800s and early 1900s?
It's definitely within the realm of possibility....in fact, one of the first homesteaders in Washington, period, was an African-American.....but for Oregon, at least, you'd need to find some way to eliminate, or at least reduce the severity of, the "Black Laws"; the main reason for this, from what I've read, was basically, more than anything else, largely to appease otherwise pro-slavery(and/or anti-abolitionist) elements who'd rather not have had any blacks at all, rather than all blacks being free, in a territory that was, at that point, inevitably going to become a free state.
California, on the other hand, already had a decently established black population, if perhaps a small one, by 1860, at least around the S.F. Bay Area. Now, given the times, there probably will be *some* limits on how many blacks can actually settle in the state(which will probably vary by location), initially, with these restrictions being gradually lifted as time goes on.
And, of course, for the Plains, all that's really needed to get started is for the 40 Acres and a Mule plan to be made an
official, and coherent policy,
and reshaped into not *just* an opportunity to reclaim land in the South, but to open up the opprotunities to buy land in the Midwest as well, or at least, what was to be Nebraska, the Dakotas and Wyoming in our world. Which wouldn't be all that hard to start, given the fact that quite a few Yankees did sympathized with the plight of the black during the Civil War; the one significant problem might be conflicts that could happen between individuals later on as more and more people strike out for the West.
I mean, really, there are a surprising number of things that could believably have happened, perhaps even without any difficulty, but didn't IOTL, for a variety of reasons.